Home Forums Reloading Big Game Rifles Remington 760 .270 Win Loads & Pressure

I've got a 1953 Remington 760 "5 Diamond" in a .270 Win that I inherited from my Grandfather. I'm very familiar with loading for the .270 Win, but I've been disappointed with the pressure limitations of this rifle. With both 130 and 150 grain bullets I'm reaching maximum pressure without getting much velocity. Max load with the 150 gr. Hornady Interlock Spire point is 54.5 gr. H4831SC, chronographed at about 2750 fps. Anything more and I have extraction issues and flat-ish primers. Quikload estimates the pressure of that load at about 53000 psi, which should be a mild load. I'm betting even the factory .270s are loaded a little hotter, but I haven't shot any through it. I'm using a set of standard sizing dies and usually neck size. Any thoughts on small base dies? I've never used them, and I don't know if it would have anything to do with this. Just thought I'd see if anyone has any similar experiences with a 760 before I make up my mind that it's just not going to tolerate full house loads.

Thanks,
JW

Definitely not good practice, but I forgot to mention my grandfather was notorious for filling up a case full of the old surplus H4831 and seating a bullet. Apparently he didn't have any issues with it.

I like those rifles and they are common around Pennsy farms. Your grandfathers practice of filling a case with the surplus 4831 is not as crazy as it might sound. I don't believe you can get to much of this powder into a 270 case.
Some of us believe that the current 7828 is, in fact, a reincarnation of that old powder.
Take a look at Hodgdens data. Their info show your load generationg higher pressure than the Quikload results you mention. 2750fps is approaching max velocity for a 150 gr bullet out of many 270's. You are 1.2 gr below their max loading.
Small base dies would likely be a step in the wrong direction as it would only work your brass even more, to no advantage.
As you say that you are intimate with reloading the 270, it might be worthwhile to have a gunsmith look over your rifle. The 270 has alway been a high intensity caliber, and the 760's handled them as they should.
I kinda think the only issue is with your Quikload guesstimate.

I like mine a lot too, it's a great rifle and a classic. I load 62 grains of 7828SSC in my Ruger Hawkeye 22" barrel and my 1950 Winchester Model 70 24" barrel with 130 grainers for velocities of 3165 fps and 3215 fps, respectively. I can easily get ~3000+ fps out of the 150s in my Ruger and Model 70 with 7828SSC or RL-22 with reasonable pressures.

I have some older reloading manuals that have 58 gr. H4831 as a max load for the 150's which is why I'm wondering why mine is maxing out at 54.5. However, I just checked the new Hodgdon data and most of the loads are around the 2700-2800 fps range...guess I'm where I should be according to the new data. Maybe I'll try some 7828 and see how it does with that.

I rechecked my water weight case capacity and 3 fire formed cases weighed an average of 69.13 gr, estimating the pressure lower than I thought for 54.5 gr. H4831SC - 50141 psi, but also 100 fps slower than my chronographed velocities. Not sure where to go from here other than doing some more loading and range work. Plus, a couple hundred fps is not much to worry about as long as the accuracy is there. I just got a little curious about it.

JW

I once owned such a rifle and also filled the case with surplus 4831 and stuffed in a 130 grain bullet....worked just fine and never a sign of pressure.

May I suggest you do a thourough job of eliminating copper fowling.....and try again.....if it's significant it can raise pressures!

Okay, I'll try giving it a good cleaning. I haven't shot any hotter loads in it in a while, but the reason I backed way off on my charges was because it would hang up pretty consistently. I assumed it was just too hot of a load, but now that I think about it, the bolt will open up slightly and hang up on the stopper. It could be released by going forward with the pump and holding the release on the trigger guard. Might have something mechanical going on as well.

JW

I know I'm guilty of trying to squeeze the most out of my guns so I hear what you're saying BUT, if it shoots well, I wouldn't worry too much about it.

You're only about 100 fps behind factory ammo for a 150 grn (and I believe that's with a 24" barrel) so it won't make or break you and nothing you shoot will likely know the difference.

I had a Rem 760 in a rechambered Whelen (from 35 Rem) large chamber showed a lot pressure. Helped a lot to fireform case
to chamber with a false shoulder, then set dies to that rifle.

Best to have separate die for each rifle in same cartridge.

Have a 760 in 06 and a 35 Whelen in a 7600 with tight chambers
can handle max loads, with no extraction problems, and long case life. I dislike large chambers and the issues they cause!!
Try a fired case from your 760, in another tight chamber rifle.

Tried some max loads in a 7600 270 Win I had briefly and they shot well and extracted easily. They were max loads from my bolt action 270 Win.

I recently tried some small base dies and it seemed to help a little, but it's still hanging up with full house loads. Primers look okay so I don't think there's excessive pressure. She seams to shoot better as loads approach maximum, which is frustrating. I recently ordered a flexible chamber cleaning tool, so a thorough chamber cleaning is the next step. The other thing I noticed was that there is some slack in the action. Perhaps the action bar lock is worn? The action bar lock catches on the complementary part of the bolt when it hangs up. I have to come forward with the slide and try to push the action bar lock release to extract the fired case.

JW

The slack in the action might be part of the problem, but I read your posts and didn't notice you mentioning the brand of brass.

I've seen some soft brass recently, even in major brands. In fact my wife's .257 Roberts started having VERY heavy bolt-lift with the same powder, primer, bullet and brand of brass (Remington) that we've used in the rifle for years.

The powder, primers and bullets were all from the same lot, but the brass was a new lot of Remington. We switched to Winchester brass with the same load and she could open the bolt with her little finger.

Thanks for the suggestion. I've been using Remington brass that I purchased a couple years ago. I think I have some Winchester brass laying around somewhere. I'll give that a try along with a good chamber cleaning.

JW

I have also experienced problems with some newer Remington nickel plated .270 brass lately. I got very hard extraction and ejector marks on the case heads, using 61 grs. of WWII surplus 4831 with a 130 gr. bullet, a load that had always been trouble-free in the past.

I fired 2 rounds and stopped, thinking I might have used the wrong powder. However, after pulling the bullets, I found that the powder type and charge were correct. I believe the brass was too soft.

Here's a picture of the action bar lock and the gap between it and the complementary part of the bolt.

JW

Just got back from the range. I fired a max load of 7828SSC behind a 150 Hornady Interlock as follows: 3 Federal Cases & 3 Winchester Cases with standard full length sizing and 3 Federal & 3 Winchester cases using small base dies. Had 5/6 hang up with standard dies & 3/6 (1 Winchester & 2 Federal) with small base dies. The Winchester cases seemed to be a little better than the Remingtons previously used and were a lot better than the Federal Cases which showed pressure signs. It's still hanging up on the action bolt lock, and will only free if I use my thumb to push it down out of the way. I think I'm going to order a new action bolt lock from Numrich. Not sure what else to do.

JW

Remingtons service manual says thay there should be .010" gap between the lock and the action bar . From your picture I think I see alot more gap than there should be . I usually fix them by putting a dollop of weld on the end to build it back up , then file to fit . That being said , I don't believe that's the cause of your problem . Have you taken a good look at the chamber ? The first thing I would do with it if it came to me for repair is , pull the barrel and have a go at that chamber . The symptoms you describe lead me to beleive that you have a rusty chamber , and maybe some pitting too , 9 out of 10 times that's the problem . Scrub the heck out of that chamber and then give it a good polishing with Flitz or Simichrome metal polish . I do this with a bore mop chucked in a cordless drill , in low gear . Smallbase dies solve chambering issues , and have no bearing on extraction !

Some times when you oversize brass to a large chamber you will experience hard extraction. On a pump 760 in 35 Whelen my rifle would do exact same thing. On factory 270 Win does primer extrude
on firing?

Thanks for the help and suggestions.

Oneoldsap - How difficult is it to take down a 760 and pull the barrel? I've got a flexible chamber cleaning tool that I could disconnect from the screwdriver handle and chuck to a drill. Probably would be easier than a complete takedown. What solvent do you use for scrubbing the chamber?

kk alaska - I haven't fired any factories through it, but I haven't had any primers extrude on firing with my handloads.

Thanks again,
JW

Looks like a complete take-down won't be necessary. I used that flexible chamber cleaning tool and turned it with my drill. I spent a couple hours on it and gave it a good cleaning. The chamber is now clean and bright without any pitting. It was pretty dirty with some signs of rust. We'll see how she shoots tomorrow.

JW

It's really not a difficult project to take the barrel off . I have a special wrench that I use , but a proper sized punch can be use to loosen the action tube/barrel nut . If you have the early model with the long action tube , don't try to turn that cap on the end of the action tube , it is staked in place and holds the brush guard in place . You can remove the action bar and bolt after you slide the action tube out . The brushguard will come right along with it , it's not attached to the barrel . I take mine apart once a year to check for rust and rewax all the steel that you can't see or reach when the rifle is assembled .