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Posted By: fortymile Tight Chamber - 01/07/20
I have a Remington 788, .22-250, which I had re-barreled to .22-250 AI. The gunsmith said he tends to chamber his rifles on the tight side, and I would say that he did in my case. I just sent a couple fired cases to Hornady to have them modified for use with their OAL comparator gauge. The cases are new Lapua brass, fired once for fire-forming with a 75 grain bullet and book maximum load of RL19 (for .standard .22-250). They were deprimed in a universal depriming die, with no sizing whatsoever. The case necks inside diameter is still slightly below bullet diameter, because a .boat-tail bullet is hard to push back into the neck by hand, and when I did get one in I had to use a kinetic bullet puller to get it out (could have used pliers but I didn't want to ruin the bullet). The rifle shoots well, and the brass doesn't show pressure signs (some has been fired a couple times after fire forming with max loads of RL-19 and 75 grain ELD-M bullets) but I do get heavy bolt lift at times. I have only been neck sizing though so the bolt lift may be more of an indication of a need to bump the shoulder back (which I plan to do next time I reload a batch). My question is, do I need to turn the necks on my brass for this chamber, or is this level of neck tension OK? I am using Redding bushing dies, with a bushing size .0002 smaller than neck thickness of a loaded round.
Posted By: FTR_Shooter Re: Tight Chamber - 01/07/20
I'm guessing your bushing size is .002 smaller not .0002.

I am NOT a fan of neck only sizing because of the inherent lack of consistency from loading to loading. I like to put everything back to a known size for every loading, including case length. I always full length resize and trim at each loading for utmost consistency.
Posted By: Tejano Re: Tight Chamber - 01/07/20
Not a writer nor an expert but what you posted sends up a couple of red flags to me. If a bullet will not seat in an un-sized case then this is an indication you need more room for expansion. I would scim trim the case necks looking to remove about 0.001-2 from them, if for hunting loads then 0.003".

Be careful if you switch brass as some could develop high pressures if they were only slightly thicker. I just went through this routine with one of my newer rifles. The chamber reamer was from a competition shooter and I had asked for a minimal no turn neck, I got a chamber that needs neck turning with anything thicker than Winchester brass. Ultimately it will be more accurate but a step I had hoped to avoid. Even if your loads are mild go ahead and turn or ream the necks.
Posted By: fortymile Re: Tight Chamber - 01/07/20
Thanks for the replies. I have watched some youtube videos recently that have convinced me that full length resizing is a better option than neck sizing only, as you pointed out. You're right, the bushing is 2 thousands smaller (.002), I wrote that incorrectly. Tejano thanks for the neck turning advice - I think that's probably going to be necessary with this Lapua brass. I've never turned necks before so that's going to be a learning curve for me as well.
Posted By: aalf Re: Tight Chamber - 01/07/20
The redneck way of determining clearance is to see if a bullet will slide back into a fired case.

The proper way is to measure a loaded round with your brass & bullet of choice, and to have a chamber cast made to determine actual neck diameter of your chamber.

The smith should at least have the neck measurement of his reamer available, and you can back into it by adjusting neck thickness vs desired clearance.

Of course next up is buying neck turning tools and good quality micrometers, regular and ball.

Or look for brass with thinner necks.

Full length size every time......
Posted By: FTR_Shooter Re: Tight Chamber - 01/07/20
Originally Posted by fortymile
Thanks for the replies. I have watched some youtube videos recently that have convinced me that full length resizing is a better option than neck sizing only, as you pointed out. You're right, the bushing is 2 thousands smaller (.002), I wrote that incorrectly. Tejano thanks for the neck turning advice - I think that's probably going to be necessary with this Lapua brass. I've never turned necks before so that's going to be a learning curve for me as well.

I've read the OP again after looking at the other answers and I'm a tad confused.

In the OP you discuss pushing a bullet into the neck and having to use a kinetic bullet puller to extract the bullet. My first reading of that part indicate to me that this is AFTER sizing the case. Reading again now, seems to indicate that this is BEFORE sizing the case, hence my confusion.

If this situation exists BEFORE you resize the case, in other words, this occurs with a fired case, then yeah, you have an issue and you absolutely need to turn the necks some.
Posted By: z1r Re: Tight Chamber - 01/07/20
Well, to start with and to avoid a bunch of endless guessing, contact your "Gunsmith" to see what exact;y he means when he says he chambers on the tight side, he can give you the reamer specs.

Some mean they tend to short chamber so the parent cartridge gets more of a crush fit in the chamber. Some mean, they use an undersized chamber reamer to cut an overall tighter chamber. Some simply mean they use a reamer that cuts a tighter neck, or perhaps shorter leade. As I said, "tight" can mean many things, best to contact the smith and see what it means to him when he says he cuts a tight chamber.
Posted By: fortymile Re: Tight Chamber - 01/07/20
FTR Shooter, yes a fired case, not resized, does not allow a bullet to easily be pushed into the case mouth. It can be done by hand, but takes some effort, and the bullet isn't easy to remove by hand either. In fact I got one stuck and couldn't pull it out using my fingers, so I used the kinetic bullet puller to remove it. It's definitely too tight to effectively use the Hornady Lock n Load tool to measure seating depth to land engagement.

I will take the advice of contacting my gunsmith to get the reamer specs. I wonder how hard it would be to have my gunsmith open up the neck area slightly? I'd rather not turn necks if I can avoid it, and I also prefer the Lapua brass.

Thanks for the replies.
Posted By: FTR_Shooter Re: Tight Chamber - 01/07/20
Fortymile, you definitely need to address this situation. In my experience, Lapua has some of the thickest necks in the .308 brass that I am familiar with, whereas Winchester is some of the thinnest. I have bushings for both and the difference is .006 if I remember right. I'm all about Lapua for the last several years so I totally understand you desire to stay with that brand of brass. A competent gunsmith should be able to open up the neck area by a couple thou. Turning the necks is really about uniforming them, not really making them thinner overall. Or at least, that's the way I see it and I agree you don't want to be forced into it if you can safely avoid it.
Posted By: fortymile Re: Tight Chamber - 01/07/20
FTR Shooter, thanks for those comments. I contacted my gunsmith and he used a standard Manson .22-250 AI reamer from Brownell's. It's a Benchmark stainless barrel. I believe the reamer was a new one as he didn't have one on hand when I brought the rifle to him. He's fairly new in the gunsmithing trade but all indications are that he does good work. So I would think the dimensions would be adequate even for Lapua brass. I do know that brass springs back a little after expansion during firing, so maybe I'm overthinking this. I took a .22 cal brass brush and scrubbed the inside of a fired case for a bit, and while bullets were still pretty snug I could push them in and out of the case by hand, so the difference between a snug fit and falling in and out of the case is probably less than a thousandth of an inch. I think I will full length resize my next batch of loads, and using the same powder charge check for signs of pressure. I do appreciate your comments and my next step if there are pressure signs will be a slight turning of the necks.
Posted By: 1minute Re: Tight Chamber - 01/07/20
Yes. with a little more science and some anal brass prep (length and wall thickness), I think one has a good unit there. Casual shooters though don't typically want to delve into that realm. Would have been good though for the builder to have furnished some accurate details on neck dimensions.

On neck sizing: That's my method for decades, and if my brass comes out of a rifle, it has always gone back in. I've never had to bump shoulders even on Weatherby cartridges that I admittedly run hot. Take that ammo to another rifle though and one may have issues.
Posted By: fortymile Re: Tight Chamber - 01/07/20
1minute, I've generally been a neck sizer myself, although only recently started using bushing dies. I am inclined to believe guys like FTR shooter when he talks about the virtues of FL resizing/trimming to yield the most consistency. It seems like almost all of the competitive shooters do this currently, but they do it using careful measurements so that they're only setting back the shoulder a couple thousandths. If I FL resize and I'm still getting hard bolt lift, then I will have to assume that my pressures are too high, and do something to address that as FTR Shooter advised. I'm just kinda puzzled that a standard, high quality chamber reamer would leave the neck area as undersized as mine seems to be.
Posted By: Dave_Skinner Re: Tight Chamber - 01/07/20
Forty, I think you've got a good chamber there, although you might need to adjust your techniques to match it. If a fired, unsized case, with the bolt out of the gun, easily seats fully and drops out or maybe needs just a little fingernail for extraction, that's a really good fit that will be totally-minimal brass working.
And to be truly minimal, you'll need to monitor your neck-wall thickness, at least measuring any new brass for fit.
One thing I would do right away is make sure you've got some expansion room for the neck to release, and you don't need a cast for that. Seat your bullet making sure it's short of throat contact, and again, hand feed that cartridge, see if it falls out on its own, see if it drags on insertion. If you can't seat it with your pinky, if it hangs up, that's getting into benchrest voodoo territory, of "fitted necks" and really zero-tolerance handloading. Some of these benchrest guys fit stuff so perfectly, the neck releases and doesn't need to be resized for the next shot. Which is ridiculous to me, personally.
But I have a couple of rifles where all I have to do is pick the bushing that gives me just the right amount of grab, and then size only the part of the neck that the bullet touches. That gives me lots of "centering," at the base, at the shoulder, at the neck false shoulder, and finally, where the bullet meets the throat. The brass I have lasts, and lasts, and lasts. Those rifles shoot better than I do, are real confidence-enhancers for me.
Posted By: fortymile Re: Tight Chamber - 01/08/20
I tried what you suggested Dave - hand fed a cartridge. It didn't hang up, went in and out fairly easily. For what it's worth, I measured several fired, unsized cases, outside neck diameter. They came out to 0.2530 inches. The collet I'm using in the sizing die is 0.2510. So i'm only sizing the necks 2 thousandths. That's probably good for case life. I never really made measurements like that before, so I don't know what the averages are. Sized cases with bullets seated in them come out at 0.2520. So the case is coming out of the barrel after being fired 1 thousandth of an inch wider in the neck than it was before firing. Maybe someone can opine on whether that is enough.
Posted By: Azshooter Re: Tight Chamber - 01/08/20
IMO you should KNOW the neck dimension! You said: reamer is a standard Manson .22-250 AI reamer from Brownell's". Call Brownells and Manson and find out.
Posted By: CGPAUL Re: Tight Chamber - 01/08/20
That`s 1/2 thou to a side, not enough to cover variences in brass neck thickness IME. Also, depending on the type of case trimmer you use, think about an inside neck reamer. Lapua case necks are normally very uniform in thickness, note "normally", so inside reaming would give you a very good finished product. I have had Winchester brass with thick necks, also Star Line, so that problem is not unusual. I do the bullet slide in test on all my newly chambered rifles...saves some grief in the long run.
Posted By: fortymile Re: Tight Chamber - 01/08/20
I e-mailed David Manson and he sent me the drawing for that reamer (Thanks for the suggestion Azshooter). Neck diameter is 0.255. My loaded Lapua cartridges measure .252. So there should be 3 thousandths of clearance total (1.5 per side) in the chamber of my rifle, on average. Any thoughts on the adequacy of that amount of neck clearance? Edited to add: I did a google search and there are some competition shooters out there who neck turn to achieve 2 thousandths of clearance but the average minimums seem to be 3 to 5 thousandths to give a "clean" bullet release. I think I will stop worrying about it, but I am going to change to FL sizing and obviously keep an eye on pressure signs.
Posted By: Dave_Skinner Re: Tight Chamber - 01/09/20
I've been away for a couple of days, but I wouldn't be concerned with three thousandths, that's actually pretty nice. I agree you should KNOW your neck diameter on the reamer, if its a 255 and you have an actual 256-257, that's still pretty within good tolerance.


Couple more things:

Loadeds are 252? With a 251 unloaded but sized? Fired 253? From that --

If the neck is 255 nominal, and fired brass 253, that's about right taking "spring back" into consideration, brass bloats upon full pressure and then springs back smaller once the gas is out the barrel. That's why we can extract cases normally, at NORMAL pressures, which do not exceed the elastic limit of the brass (and barrel steel to a certain degree). Super hot loads not only bloat the brass, but also the barrel steel, and when the pressure returns to zero, the brass molded itself to the bigger steel, and to your extractor/ejector cut. Bad juju, that.

So I like your numbers so far.

One number you'll need to memorize now is 255, and loaded diameter of neck at 252, MAYBE 253 if you really want to get precise. But 252 should be our target for loaded necks, anything fatter needs turning to make SURE the brass comes away from the bullet upon firing and bullet "release" into the rifling. So, whenever you get new brass, just stuff in a bullet and measure your finished outside diameter. If it is more than 252, then it's smart to outside neck turn, and to turn all the way down to the neck-shoulder junction to make sure the INSIDE diameter is the same all the way from top to bottom and the bullet isn't being collared by "The Dreaded Doughnut." Basically, a ring of brass that acts like a choke collar on the bullet when chambered. A bad thing.
As things are, as long as your fired rounds finish under or at 252, you're in good shape.

Inside versus outside? Inside doesn't follow the brass variations. Outside first, and THEN maybe with the right inside reamer for "dressing" and to zap any possible doughnut evil. Doughnuts are evil. If your necks are icky and lumpy, outside reaming will show you that right away. So the steps are:

Initial size with expander ball, to make the neck round on the inside (it follows the last thing it touches, the ball).
Outside ream, but only enough to make things round. And if you do this, you have to do all the cases in the batch exactly the same
There should NOT be a doughnut at this point unless you are necking something down or changing the shoulder.
You should have a neck that is round and consistent both inside and outside.

Now our issue is how tight do we want the neck to be on the bullet. You can control that with your bushings, very precisely. I have 247 through 253 neck bushings for my 22s. I use the 248 and 249 the most, which translates out from fired to sized of about four thousandths, ie, fired 252 gets a 248 and ends up 251 or 252 loaded. So that's "four":thou of "grab." How much is right depends, but three or four is normal for my rifles.
With your 251 sizer, that's two thou of grab, which might be less depending on how springy your cases are. I would get and try both 249 and 250 as a start. The concept you need to think about is, if there's a half-thou of variance, a half of 1 is 50 percent. A half against 2 is 25 percent, a half against 3 is 16 percent -- the idea is consistent pull without mashing your brass down and working it too hard. Too much is when you can see where the bullet stops in the neck, it measures fat where the bullet is, and skinny behind the bullet and in front of the shoulder.

"Pull" is important at the start of the ignition cycle. The powder starts to burn, and the rate of increase of the pressure should be a smooth curve. If there's not enough pull, the bullet moves (Mic McPherson wrote about this many times) before it should, then bumps up against the rifling, and there's a little blip there that affects final velocity. How much depends on the powder and how the bullet is seated in relation to the throat. But it can be a lot. So, consistently starting the bullet at the same point in the ignition cycle is a goal of all this.

Anyway, I think you're going to be real happy with your new chamber.
Posted By: fortymile Re: Tight Chamber - 01/10/20
Dave, that's a very thorough explanation, and I appreciate it. At the time I ordered the bushing for my Redding die, I had kind of a cheap dial caliper. Best I could tell my loaded rounds measured .253, and some precision reloading videos I had seen recommended going 2 thousandths less on the bushing. Recently I ordered a decent digital caliper, and the measurement of loaded rounds came out at .252 very consistently. I will get a couple of smaller bushings as you suggest. I have seen references to the "dreaded doughnut" but didn't know what that meant - thanks for covering that. You've given me a lot of good information and advice here. Thanks for taking the time.
Posted By: mathman Re: Tight Chamber - 01/10/20
Outside turn

Inside ream
Posted By: Dave_Skinner Re: Tight Chamber - 01/11/20
Yep, turn and ream are different.
Let us know how this all ends up, Forty. I think you're on the path to happiness.
Posted By: butchlambert1 Re: Tight Chamber - 01/12/20
Do you have a good way to check headspace on your fired rounds to compare to your chamber? You do not want to bump the shoulder until you know where you happen to be. I fell into bumping until mine chambered and extracted easy. Remember that when you bump you are also sizing the base a little more. Problem is you may start having case head separation from bumping too much. Have your gunsmith make a gizzy (headspace gauge) using the chambering reamer. Have him take a barrel cutoff and run the reamer until the shoulder is cut in the gizzy. Put your fired, unsized, and primer less brass in it and measure. You can then measure and adjust your die to bump no more than .002". Using your figures it should not be a neck diameter problem. Have you measured the base of your brass yet?
Posted By: fortymile Re: Tight Chamber - 01/13/20
Butch, I have an order in to Brownell's for a bump gauge and comparator insert setup, so with that I should be able to measure the shoulder bump and keep it at .002 so I am not working the brass too much. I like your idea of having my gunsmith make a gizzy so I may contact him to see what that would cost. Would probably be the most precise way to do what I'm trying to do. My batch of new, unfired Lapua brass measures .466 at the base. After firing, unsized brass also measures .466. The reamer measures .467 at the base. So I think, as Dave Skinner said, and it sounds like you agree, my chamber should be a good fit with the Lapua brass I'm using. Minimum clearances but that should help brass life as long as I don't overdo it on the resizing. Thanks for your suggestions.
Posted By: fortymile Re: Tight Chamber - 02/10/20
Dave Skinner asked me to post a follow up when I got this issue sorted out, so here's the follow up. I have been doing more loading and shooting, and I believe my concerns were unfounded. Yes the chamber is on the tight side with Lapua brass, particularly in the neck, but not excessively tight. I think I'm getting a good bullet release. I've decided to order a Ti Nitride bushing for the Redding die a little smaller than what I'm currently using. My .251 is only giving me a thousandth or two of constriction so I ordered a .249 to provide just a little more neck tension. I've got my body die set to bump the shoulder back .002. Cases feed without issue. Decided to try H4831 with the 75 grain ELD-M bullets and a trip to the range on Saturday gave me several 5 shot groups around 0.6 to 0.7 inch at 100, and that's good enough for me. I'm using CCI-200 primers, and I think on my next loads I will try CCI-250s just to see if it makes any difference. One more note, I changed scopes from an old Leupold 16X to a Meopta 4.5-14X. The Meopta is very clear and was very easy to sight in; no Leupold dance. The turrets are much more low profile than the Leupold and that solved an issue with ejected rounds bouncing back into the ejector port. Very happy with the rifle and the scope at this point.
Posted By: Armednfree Re: Tight Chamber - 02/10/20
Actually you only need .002 for release. That means you have to cast your chamber and measure the neck. You will be turning the necks so that with a seated bullet it comes out to spec IN ALL DIRECTIONS. You are safer going .004 on that size which to me always seemed to work just as well.

You are not going to have a great deal of neck tension. Figure on firing single shot as you don't want bullets moving in the magazine.

You then can seat where you want, or seat with the rifle. That means the bullet is in contact with the lead and is pushed into the case when the bolt closes. With that throw your data away and start over from the bottom.

I contact seat in my 284. I ended up a full 2.5 grains less of H4831sc than book max. Note that when you chamber you have to fire the round because the bullet will stay with the barrel. Otherwise you have to elevate the muzzle, remove the case and tap he bullet with a rod.


Now I don't mean you just put the bullet in and jam it home. In my 284 it's .005 beyond contact.

Posted By: fortymile Re: Tight Chamber - 02/10/20
Thanks for the info Armednfree.. I've measured base-to-ogive and I'm aiming for about .02 of jump to the lands. Those long 75 grain bullets at that seating depth don't come close to fitting in the magazine. One of the drawbacks of using a model 788. I don't mind loading one at a time though. I don't think I want to try seating with the rifle, although it's an interesting idea. It's going to be a coyote and prairie dog rifle (prairie dogs it will be accompanied by a .223 and be used more sparingly for longer range shots).
Posted By: Armednfree Re: Tight Chamber - 02/10/20
Originally Posted by fortymile
Thanks for the info Armednfree.. I've measured base-to-ogive and I'm aiming for about .02 of jump to the lands. Those long 75 grain bullets at that seating depth don't come close to fitting in the magazine. One of the drawbacks of using a model 788. I don't mind loading one at a time though. I don't think I want to try seating with the rifle, although it's an interesting idea. It's going to be a coyote and prairie dog rifle (prairie dogs it will be accompanied by a .223 and be used more sparingly for longer range shots).

What I told you was all bench rest stuff. The accuracy requirements you need are not nearly that high. I'm talking about shaving .1 off a group, that doesn't mean anything in your objective.
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