Hi all, Im a big fan of the Savage 99 having owned a few. I currently have one 99F 308 win, made in the 60s? that apparantly has a tight bore. It cannot shoot factory 150gr rounds without locking the action or nearly so. Handloads show pressure at the STARTING level. Ive taken it back to the shop and they scrubbed the chamber because it was thought that was the issue. Helped a tiny bit. Last summer had a different shop to the same thing and again it helped a bit. I have not had the bore slugged.
I handload so its not s super big problem but it would be nice to get normal velocities out this 22" 308. I currently load a 150 SST to 2650.

Anyone have any experience with this?

had a 308 and a 243 do the same , polish the chamber some more

norm

Thanks a lot Norm, I will!

Get the barrel slugged too. Strange things happen from time to time. Might just be a tight chamber though as Norm suggested. Had a 30-06 like that once. Chamber was just under spec and pressures got high quick. Velocity was fine though given that the pressure was in the right place with the lighter loads due to that tight chamber.

Thanks Skidrow! I will do that, just to know for sure if nothing else. Ive only had a chrony since the end of august so i really only got to test two loads that I had worked up. I am planning to load a few of the others I had tried before and see if their velocity is in the normal range. Im optimistic that I can find something that works even if the next chamber polishing doesnt result do the trick all the way.

Could be a situation where the guys in the barrel shop at Savage re-ground a chamber reamer one too many times, and went ahead and used it anyway. Not saying that Savage quality control slipped in the 60's, but...

I would pull the barrel and run a fresh reamer in the chamber. Even if the bore dimensions were a thousandth or so undersize it shouldn't cause a hellaceous spike in pressure. On the other hand, if they screwed up and ran a .308 reamer into a .284 barrel...

Biggest issue isn't the undersize chamber body. If that were the case you would find it difficult to chamber a factory round. Rather, if the neck area of the chamber were significantly undersize there wouldn't be room for the case neck to expand sufficiently to release the bullet freely upon discharge. That situation will drive up pressures too. Perhaps a bit of neck turning (not neck reaming in this instance) of a trial batch of handloads would be in order. Just a couple thousandths of an inch would work wonders. Perhaps too, a chamber cast would be in order to get a clear vision of what you're dealing with before running up a bill with a gunsmith.

Just thinking out loud.

..you'd have the only factory 7mm-08 F!! ..just need a wrap of duct tape at the neck,..case neck, not my neck.

I go with gnoahhh, it is probably the neck area in the chamber or the free bore to tight and pushing the bullet back into the case. If the chamber is correct the barrel can be undersize and there will be no noticeable increase in pressure. This is a proven fact. Is the end of the neck curled in (Looks like someone tried to roll crimp it) on fired cases? I have seen this already and it indicates the neck area is too short or the case was not trimmed enough. Trimming/turning the neck on a few cases is a good idea and a good place to start. Take a reformed, empty case and try to drop it in the chamber. It should go all the way in. If not, lever it in and then take a close look at the brass after it is extracted. Start small and progress from there. No need to jump to (Expensive) conclusions. Let us know what you come up with.

A too tight neck can be checked easily without a chamber cast. Take a fired case (from the rifle being discussed) and slip one of the bullets that you are loading into the mouth. If it slips in without any resistance (as it should in a factory chamber), it is unlikely the chamber neck is too tight.

Indeed. I'm so used to automatically doing a chamber cast on everything before starting to load for them that I sometimes suggest that without thinking that others aren't as anal as me (when it comes to handloading)! I like chamber casts for showing me how the throat/leade are configured too, as that info is necessary to get a good fit with a cast bullet, which is mainly what I shoot.

That will not show if the freebore is undersize. I used to make reamers and the freebore tolerance is in tenths. It is very likely that the problem is the neck or freebore area causing the pressure jump.

This is some good info folks, thanks! I need to start playing around with this gun some more to figure this out once and for all. I have had it since 2008 and have shot a couple hundred handload through it but Im ready to have it shoot normal loads so I can really shoot it. My "hottest loads are book starting loads or a tiny bit above. And that has only been possible after the 3rd trip to the shop, where they did the polishing mentioned above.

So to state the some facts, factory rounds chamber just fine, as have all my handloads using book listed C.O.A.L lengths with 3 different bullets. I did shorten the SST loads by .01 fore better loading reliability under pressure but there was nothing hot about them before. I have not noticed the brass being pinched/scrunched/crimped at the neck after firing but I will fire some more and check extra careful just to make sure.

The freebore length, is the only way to check that via chamber cast? A starting load with the Speer 130 HP out of the Speer manual, (not this new one, but one before 13th?) using the specified COAL showed frosty cases and sticky extraction. That round being much shorter than the 150 Speer btsp and Hornady 150 SST I have also used. Does this suggest that freebore isnt within a normal standard? Or at least one of if not the sole problem?

Doesn't that say something about the surface finish in the chamber, as in rough and grabby?

There's a slight misinterpretation of terms here, too. Throat= that short section between the chamber neck and the beginning of the the rifling. Also called the "ball seat", it supports the bullet before its journey up the tube, and is a critical dimension. Freebore= an extra long throat designed to allow a bullet to get a good running start before jamming itself into the rifling. It was/is a means of extracting a little more velocity while keeping pressures sane. Probably the best known historical use of freebore was by Roy Weatherby in his magnums, after which various builders have employed it over the years with varying degrees of success. The trade off is potentially poor accuracy if the bullet doesn't fit it well as there is more chance for wobble as it starts its journey into the rifling.

Benchrest competitors are anal about a myriad of things, not least of which is chamber neck dimensions, case neck I.D.'s and O.D.'s, bullet tension, throat dimensions, etc., etc. We plebian shooters are content that those who service us adhere to SAAMI dimensions in our chambers/throats, factory ammo, bullets, and reloading dies- all of which take into account manufacturing tolerances and ensure our general safety while providing a satisfactory level of accuracy. We can't expect eye popping accuracy unless by luck (or by design) we select a grouping of chamber/throats, ammo, bullets, dies, etc. that serendipitously fall within as narrow a set of tolerances as possible. People who take this seriously, and know how to use a micrometer (or have a gun mechanic in his hip pocket who does), will employ many of the precepts of the benchrest crowd. The vast majority of shooters roll the dice, experiment un-scientifically, follow internet advice without verification, and on-and-on ad nauseum. On top of that we tend to forget that the tiniest of variation in dimensions anywhere in this area can cause gross variations in pressure- either to the good or to the bad.

When one stops and considers the dizzying number of variables in the makeup of the machine that delivers our projectiles to their targets, and the design of the ammunition we feed them, added to the mental and physical mechanics of shooting, it's no wonder it's fascinating hobby that defies mastering over a long lifetime.

That is EXACTLY what I was ready to post...give or take a few words.

Well put, Gary!


I think the difference between the Rem .223 and the military 5.56 rounds falls in this area. It's why you should not fire the 5.56 in a .223 chamber.

5.56mm
.223"

Good observation.

Also, it is consistent with the slightly improved extraction after each of the the two chamber polishings by gunsmiths.

OP: can you post pics of the brass before firing and after firing?

I had a .243 with the same problem. It's now a 260 rem. And I love it

Freebore/Throat. 6 of one, half a dozen of another. "Ball"/ ojive. We get the general idea. Load up a dummy and coat the bullet with a felt tip marker. Chamber it and extract. If the bullet is getting hung up on something, it should show on the blackened area. People do weird stuff to guns. Use a screwdriver and cleaning rag in the chamber, stuff like that. Don't use blueing or something of that nature. The tolerance is so close in that area that it will scrape something with a thicker consistency off. I would still bet on the neck/freebore area. I have worked on automatics that had chamber walls so bad it looked like a tap was used instead of a reamer. The guns would not extract, but there was no pressure problems because the neck/freebore area was O.K.

Not quite the same. The cartridges are pretty much the same dimension but the chamber specs and max pressures are different. The .223 chamber is tighter and the .223 pressure is less. The 5.56 chamber has a bit of freebore that the .223 doesn't. .223 is loaded to SAAMI specs while the military spec for the 5.56 is a bit hotter. Thus problems can arise when firing 5.56 in a .223 chamber.

Never said they were the same. My post was because Rick accidentally wrote .556 rather than 5.56. I think that was his second brain fart of the year, can't just let them go unnoticed compared to my 5 brain farts per week.

It would seem that another situation that can mysteriously raise chamber pressure and cause difficult bolt opening is an over-polished bore. It's being discussed on the Cast Bullet Association forum right now. The mirror polished bore can induce more drag on a bullet as it screeches down the barrel. C.E.(Ed) Harris likens it to the effect one gets when one wrings (rubs) two Jo blocks (gage blocks) together or rubs two pieces of prism glass together to affect adhesion. Dunno, just passing it along, but it makes sense to me.

I wonder if the OP's bore was given a high polish by a well meaning experimenter.

Have not read the discussion on CBA. Curious. Any discussion of ultra smooth surface-surface adhesion for surfaces of dissimilar metals which would be the situation in brass casing in steel chambers?

Someone with more knowledge would have to answer that. Like I said, I'm just passing along some food for thought.

I dunno, I have shot a lot of chrome lined barrels already. The polished chamber exerting more back thrust against the bolt has been proven by P.O. Ackley. A rougher finished chamber has the case grabbing the chamber walls like a cat going down a chimney. More stuff to think about. I bet you guys are a hoot around a campfire with beer in a cooler. It is a fun discussion.

I've been reading gnoahhh's posts for years. I've learned stuff from what he has written.