Rem 700 cratering

[bob4]

I noticed a bit of cratering in some 270 loads I've been using. Rifle is 2 yrs old. The cratering is just enough to barely catch if you run your fingernail over the primers. I'm still under Max load by 1/2 gr with h-4831-sc /Sierra GK 130g, CCI primers, .030 off the lands and no other signs of pressure. No sticky bolt ,flattened primers or marks from ejectors.
Some reading mentioned Remington doing some of this on purpose with a beveled primer. Most of that reading is 2 yrs old though.
Should I be concerned ?

 

[dprice3844444]

anytime you see any signs of over pressure,you should pay careful attention.back off a 1/2 grain and check again.you may even have to back off a full grain and inspect brass carefully.brass weakens a bit each time it's used.how well are you grouping?

do you have a chronograph?that will also tell you what fps your working with.

 

[gahunter12]

What are your velocities? A chrono will tell you a lot about your loads. Also if your firing pin hole is a little over sized, you could see some flowing into the F pin hole. My Ruger 7mm craters primers a little from min to max.

 

[41 Mag]

Another thing is the primers your using might also be a bit softer than some of the others you have used.

I have seen where some primers show just a hint of a raised ring around the firing pin dent, while a different batch, or lot of the same type didn't. All used the same loads. I have also seen this with other brands as well. Not to any extent that I have worried about it as my loads were well within book spec's and nowhere close to high pressures.

When I see the corners ironed out flat rather than round, or if I see anything resembling that, then I start to look a LOT harder at my loads. With some powders load developed in one temperature range will be a touch hotter in a higher range. This has at times through the years shown a bit of excessive pressure which ironed out the corners pretty good.

Usually with the chrono as suggested you can pretty quickly see where things are starting to get spikey and you get a jump of 100+ or so FPS where your previous load only came up 50-75fps.

 

[bob4]

What are your velocities? A chrono will tell you a lot about your loads. My Ruger 7mm craters primers a little from min to max.

Again this is a Remington 700 in .270.
For the record this is brand new Nosler brass.
59.5g H-4831
CCI LR Primers
ogive 2.860 < Fairly certain, my book is not in front of me now
Series Shot Speed
4 1 2869 ft/s
4 2 2876 ft/s
4 3 2867 ft/s
4 4 2869 ft/s

Also if your firing pin hole is a little over sized, you could see some flowing into the F pin hole.

This is what I have been reading. Can I check this or is this for a smith ?

.how well are you grouping?

1/2 MOA And 1/2 gn higher ( Max load) the groups were incredible.

 

[gamestalker]

It's not at all unusual to see an over sized firing pin hole in the bolt face of any bolt gun, especially the new stuff for some reason.

If all other aspects of the load support normal pressures, I wouldn't be overly particularly concerned about it. However, I would imagine that an excessively over sized FP hole could cause a primer piercing issue? It's never happened to me, and I do load near the upper end of the charge tables too.

GS

 

[rogn]

A large number of rifle bolts are fixed between centers for polishing and etc. This will taper or funnel the firing pin hole. Some brands of factory ammo especially higher pressure loads are prone to this effect. There is nothing wrong but it does make you scratch your head. Brass doesn't necessarily weaken with each firing, some gets harder and stronger with light work hardening. Loose chambers and headspace as in military rifles, especially auto loaders--AK!!. These will stretch brass and after a few loadings you may have scrap brass. One at the extreme of tolerances may be just single loads. One shot and discard.

 

[steve4102]

The Rem 700 is famous for oversized bolt hole.

 

[FLIGHT762]

Remington 700's have a slight countersink in the firing pin hole in the bolt face.

If you have a Jeweler's loupe or magnifying glass, you can take the bolt out of your rifle and look at it to see the chamfer / countersink.

Normally, a cratered primer is a sign of overpressure in most rifles. You could be experiencing the primer flowing into the 700's countersink. If you're not seeing the other signs of pressure, stiff bolt lift, extractor / ejector marks / flowing into the case head, you might be okay.

This is a common occurrence in Remington 700's.

 

[bob4]

Thanks everyone. I've looked at many cases at this point many of which were loads well under where I am now and all show some small signs of the cratering.
I have some rem core- Lokts in the same 130 GN. I'll send one or 2 of then through to see what happens just for curiosity's sake.
Shame, that the last load of 1/2 gn higher produced incredible accuracy. The 1/2gn less was certainly acceptable for hunting and that's were I'll stay for a bit.

 

[beefyz]

A few above have already mentioned about the infamous Remington oversized pin hole and/or primer cratering. I had the exact thing happen to me on a brand new FTF Model 700 in 6mm. Knew something was immediately wrong. No way it was reloads/overpressure because I was shooting there own factory ammo for testing. Called Rem and there a hesitation and then ....UH... you'll have to send it back to us. Got it back, new bolt and headspaced; everything fine now but now I see these rifles are being recalled AGAIN for possible defective triggers. What has happened to Remington ??

 

[gamestalker]

What has happened to Remington quality? I don't have the energy to answer that question in full detail, other than to say, they aren't what they used to be. I just spent an enormous amount of time fixing major manufacturing flaws on a new upper shelf 700, only to have to start all over with another one next week.

Wait till you come across one that won't accept any factory ammo, been there, done that. Fortunately that issue is much easier to rectify, and in some sense almost a blessing, over getting one that is over sized, sloppy.

GS

 

[bob4]

I just spent an enormous amount of time fixing major manufacturing flaws on a new upper shelf 700, only to have to start all over with another one next week.

Sounds like job security.