Pressure Signs Help Needed

[mtang45]

I don't see anything in the pictures that indicates severe over pressure condition. As others have said difficult bolt lift is a sure sign and you indicated it was normal. I do see some light ejector marks so you are very near max pressure, but I don't think it would cause you any problems. Hard bolt lift, combined with heavy ejector marks and a much more flattened primer would be the signs of an over pressure condition.

 

[sea2summit]

IMHO reading primers is one of the least accurate and wildly variable ways to read pressure signs of the case. It can tell you other things but case pressure limit thresholds not so much. Same goes for ejector swipes but to a lesser degree.

I'm with him^

These are the results of a ladder test I did to get max load on some .30 V-Max for a 16" AR10. It's gonna be different because it's semi but no ejector swipes for me is actually uncommon out of this gun. Focus on the primers though between min load +.5 to max load, basically identical.

Gotta read everything not just primers. Based on what I see on your load I wouldn't hesitate shooting them.

 

[mtang45]

For those of you talking about ejector "swipes". There is a difference between a swipe that makes a shiny spot and an ejector dimple that obliterates the letters on the case head. Swipes are normal and happen all the time. An ejector imprint that flattens case head letters is not normal and definitely over pressure. I have not seen a picture yet in this thread that shows an over pressure ejector mark.

 

[SemperFi]

Primers ain't flat
I'm with Elk338 on primer flow I have to bush all my rems
No heavy bolt lift so I'm not on the high pressure side

I'm also not seeing any ejector marks, maybe the lighting, etc. Ejector swipes are common but the smiley face from the ejector means back off!

 

[Deleted member 107796]

My opinion is that the top case shows more cratering and shows more extractor imprint. I've seen flatter primers, especially on my 308s. The cratering on the bottom can be due to the chamfering of the bolt face where the firing pin exits, like on my Winchester 70. I would venture to say that this rifle always shows a bit of cratering, which would be a danger if you load very hot. good post

 

[JAYgs8163]

The cratering from what I've read is from space around the firing pin on Remingtons. Supposedly there's a bushing that you can have fit by a gunsmith. I'm just confused. I guess I'll load to minimum and see what it looks like...

Yes, you can have the firing pin bushed. There are numerous smiths that can do this for you and it's not that expensive to have done. <$100, your top piece of brass definitely looks to be way over pressure IMO. Also over max published data as you stated. Resize the brass and see how the primer pockets are in each fired piece. After resized see how hard it is to reprime. If pockets have been stressed the new primer will more than likely go in very easy.

 

[javman]

Looks good to me! Bolt needs to be bushed as mentioned by several and your probably close to max.

 

[Tex_Hunter]

Brass originated as Nosler Trophy Grade 160 AB factory ammo fired through the subject rifle. This is the first time it has been reloaded. So it has been fired 2x. First time as factory, and this time.

How'd the primers look on the factory ammo when you fired it?

Agree with others and have personal experience with Remingtons cratering primers on multiple rifles, even with starting loads. You still have some radius on the shoulder of the primer cups in your first picture so I disagree with whoever said they are flat.

As far as ejector marks, is your chamber clean/dry? Even a little bit of oil/fouling can give you a false positive here.

Unless you are just a speed freak though and need every last fps for some personal reason, I'd shoot a string of rounds and pick the one's that are most consistent, if you already found a node that was below that top charge you shot, then there isnt really a reason to push things, 3000fps with 160gr class isnt exactly slow.

 

[Joefrazell]

Yep firing pin needs bushed. Some of rem 700 bolts have this issue. Isn't going to matter the powder charge. I just had a gun built and the Smith had to replace the bolt and the new bolt was doing this. It's now getting bushed out. Not a problem technically but it's not right. For some reason Remington chamfered the bolt face right where the pin comes out.

 

[newmexkid]

I'm using CCI primers and RL 26 in my 280 AI. However, I'm shooting 140's. I tried H4831 and couldn't get the velocity I wanted without getting into heavy bolt lift. I'm willing to bet you would see a big difference after having the bolt bushed and the firing pin turned down. If you can find any...Try RL 26.

 

[keithcandler]

Large rifle primers can crater a lot before they pop, as a general rule of thumb. Every 257 Weatherby I have ever owned has cratered primers in the worst way imaginable at the accuracy node. I ignore craters. I have NEVER had a Remington large bolt face or magnum bolt "blank" primers due to oversize firing pins.

You can see on the bolt head that the bolt face is not square. Top end loads may show a tad bit of contact on the high side of the bolt, you can ignore this also, depending on other factors.

Very often, you get the slightest pressure signs, like in the OP's pictures, right at the top end accuracy node. Often loads are EXTREMELY accurate at this slight pressure, the cost could be primer pockets opening up. You have to make up your mind if the cost of brass is worth the accuracy, or back off on your load with less accuracy/pressure.

Nosler brass is on the softer side, since you are not experiencing increased bolt lift, then ignore the cratering. If you are not getting increased bolt lift, then you maybe anxious over nothing regarding cratering..

So, you can make brass from tougher Winchester 280 brass or the even tougher 30/06 brass made by Lapua.

OP stated that he was anxious approaching Max Reloading manual book loads. NOTE: any reloading manual you pick up will state min and max loads that is intended as an EXAMPLE for the Ballistic's Lab Test gun. This is meant to show what is safe in their barrel with their particular lot# of components.

I shoot Lapua 30/06 brass in all of my 280 AI's. The neck is a little shorter, I just clean the necks in the chamber with a pistol brush, examining with a bore scope. I do neck turn. I fire form the brass with 14.6g of bullseye, cream of wheat, and a piece of paper towel....easy. No more loose primer pockets or premature pressure signs on case heads. Lapua brass puts you in another league when it comes to taking pressure in this wonderful case. I shoot 175's at 2950 with IMR 7828 with a fed 210 primer, 26" barrels.

 

[Chamberman]

IMHO, back the bullet off. The ELD-x's seem to shoot better with a little jump, .050- .060. Seems they swage better.. Start at SAAMI OAL and work up....

Gre- Tan/GREG TANNEL does an excellent job of bushing the firing pin hole and turning the firing pin down.

 

[30BR]

... An ejector imprint that flattens case head letters is not normal and definitely over pressure. I have not seen a picture yet in this thread that shows an over pressure ejector mark.

And you will KNOW it when you see one!
BTW: https://www.gretanrifles.com/product-page/bush-firing-pin-hole-turn-pin
Buy his Steel fluted Firing Pin assembly. Probably the cheapest best replacement part you can get for a Remington, and have him fit it with the bushing.

See below for ejector marks on primers that don't look that bad. Could be from having lube on the case or chamber.

 

[Lee Goodwin]

Only thing I can think of to add is, check your scale and maybe be happy with less speed.?
sticking bolt has happened to me and if you have to tap your bolt with a piece of wood to extract a hot loaded just shot case... It ain't fun, and, it makes you think, why am I doing it this way?
in the end I think I had set my shoulder back too far, and, too many hot reloads on the cases. I was getting case head separation and pushed in brass at the neck and shoulder.
No sense in making it a more dangerous venture than it already is.