Primer Cratering Rem 700 .223

toomanyhobbies

toomanyhobbies

Regular
EE Expired
Rating - 100%
7   0   0
Location
Houston, TX
I recently bought a new Remington 700P in .223Rem. It has the 26 inch barrel, and short action. I've been getting primer cratering since day one, with factory ammo and hand-loads, but the primers don't show evidence of flattening, just the craters. I've put a picture of some of the casings below. Most of those were factory ammo.

I have an old Tikka in .222Rem that flattens the primers nicely with a max load of 27.4g of W748 pushing 50gr Sierra BlitzKings around 3300 fps. No cratering, ever.

My latest test loads were 28.0gr of H335 with the same Sierra 50gr bullets, chronographed at about 3630 fps, and also 25.0gr of Varget behind the 69gr MatchKings at 3000 fps. Cratering with these loads is approximately the same as in the photo. Bolt is not tight to open.

IMG_7319.jpg


Is there something wrong with this rifle? It seems to shoot fine, but I'm uncertain as to how much chamber pressure there is.

Thanks for your advice,
Eric
 
You can get primers that look like that if your firing pin fit is a little loose in the bolt face. It usually does not cause a problem. If it bothers you though you can have a good gunsmith fit a bushing around the pin.
 
You may get a more appropriate response in the Gunsmithing forum.

Excessive firing pin protrusion may be a problem here.





.
 
Could be fit of firing pin to firing pin hole, could be a weak firing pin spring. Inspect the fit of the firing pin & bolt. Is the pin loose in the hole? It shouldn't bind, but it shouldn't be loose either.
 
Heavy loads

Your loaded pretty heavy. Well above max. recommended for sure.
That being the case try CCI primers, as they have a harder cup.
 
slaym said:
Your loaded pretty heavy. Well above max. recommended for sure.
That being the case try CCI primers, as they have a harder cup.
Click to expand...

The picture shows 8 cases, most of which were factory loads, including milsurp at top right. The bottom four are Federal 69gr Gold Medal Match & Winchester 45g white box. The two second from the top were reloaded Federal American Eagle (Lake City) cases with 69gr SMK's on 25 gr of Varget. They all have about the same degree of cratering. That's not a max load in the Sierra book. I'm pretty sure I'm not loading too heavy. Certainly no problem opening the bolt after the shot.

I'll have a look at the bolt face ...

IMG_7478_1.jpg


IMG_7481_3.jpg
 
Last edited:
slaym said:
Your loaded pretty heavy. Well above max. recommended for sure.
Click to expand...
Why do you think they are heavy loads? The primer edges are rounded and extraction was easy.

This .308 was fired today from a Rem760. It shows higher pressure as it is flatter and has extractor mark on one side, but still not danger high.

brass005.jpg


slaym said:
That being the case try CCI primers, as they have a harder cup.
Click to expand...
A harder cup will not reduce pressure. It will only make high pressure harder to detect.


.
 
slaym said:
Your loaded pretty heavy. Well above max. recommended for sure.
That being the case try CCI primers, as they have a harder cup.
Click to expand...

Not necessarily so at all. As others have mentioned, probably caused by a firing pin a bit loose in the boltface hole. (your photo shows this to be the case) I would try another firing pin, or have the boltfaced bushed. Any decent smith can do this at a nominal fee. Regards, Eagleye.
 
Load

Looking at hogdon's max. it is 26 grns with 50 grn bullets. 3396 fps.
Not sure about anyone else, but that firing pin hole looks quit
beveled to me, rather than flush.
 
From the looks of your boltface, you have a slight chamfer milled around your firing pin hole. It could be that the pressure is causing the primer cup to flow into this area. KD
 
Thanks for the advice everybody. I didn't think it would be so easy to see this right on the bolt face, but there it is.

There does seem to be a bit of a bevel around the firing pin that lets the primer flow back into that area. Not so impressive for a month-old rifle with less than two hundred rounds through it. I guess I may need to get in touch with a gunsmith to get it fixed. Probably not much point calling Remington about warranty service.

I shot twenty rounds last Monday with 28 grains of H335 and Sierra 50 gr Blitz Kings, trying to find the best seating depth (touching the lands works best). The primers look just the same as above. This is a max load from the Sierra manual.
 
Load

I am looking at there "latest data sheets" and for a 50 grn bullet
it is 26 grns max. And max can sure depend on the power batch.
We just blew up a 700 rem 308 with 46 grn varget,,the rec. max.
took a 2 x 4 to get the bolt open.
 
Flattening of primers and sticking bolts are not the only signs of high pressures. As far as cratering goes, I'm thinking that is pretty minor.
How do your handloads shoot?
You may find loading the 69 SMKs with half a grain less (24.5 of Varget) proves to shoot just as well with marginal (50 fps) loss of velocity, and is a little easier on the throat of your barrel.
 
toomanyhobbies said:
Thanks for the advice everybody. I didn't think it would be so easy to see this right on the bolt face, but there it is.

There does seem to be a bit of a bevel around the firing pin that lets the primer flow back into that area. Not so impressive for a month-old rifle with less than two hundred rounds through it. I guess I may need to get in touch with a gunsmith to get it fixed. Probably not much point calling Remington about warranty service.

I shot twenty rounds last Monday with 28 grains of H335 and Sierra 50 gr Blitz Kings, trying to find the best seating depth (touching the lands works best). The primers look just the same as above. This is a max load from the Sierra manual.
Click to expand...

Firing pin hole is too big in diameter. Find someone who will bush bolt face and install .062 hole. Grind pin down to slip fit in this. You won't crater or blank a primer after that. You'll still be able to destroy your brass, but you won't crater or blank primers.

If factory remington bolts do this, pitty the Winchester shooters..even bigger holes.

NormB
 
I was shooting 69grn SMK's with 26grns of Varget (Max Compressed load according to load data) and no signs of pressure, flattened or cratered primers etc. in my Tikka T3 Lite SS.

Richard
 
Don't know if it is just the photo, but the boltface looks really horrible - rough, textured. The edge of the firing pin hole looks eroded. Lots of brass smearing. This was a brand new rifle, 200 rounds ago?
It would be worth contacting Remington, at least make them aware of the situation. If a gunsmith touches the bolt, you will definitely be on your own.
 
CyaN1de said:
I was shooting 69grn SMK's with 26grns of Varget (Max Compressed load according to load data) and no signs of pressure, flattened or cratered primers etc. in my Tikka T3 Lite SS.

Richard
Click to expand...

That is one of the nice things about Varget; you're likely to run out of case before you hit max pressures. You may want to try decreasing your charge though, as there comes a point where you are essentially just burning more powder with little to no gain in velocity.
 
tiriaq said:
Don't know if it is just the photo, but the boltface looks really horrible - rough, textured. The edge of the firing pin hole looks eroded. Lots of brass smearing. This was a brand new rifle, 200 rounds ago?
It would be worth contacting Remington, at least make them aware of the situation. If a gunsmith touches the bolt, you will definitely be on your own.
Click to expand...


The bolt face seems to be Parkerized or something, I agree it is really rough. I'm up to about 260 rounds now, worked on some loads for the 36gr Barnes Varmint Grenades, 50gr Sierra Blitz Kings, and 75gr Hornady A-Max rounds. Best groups are still around 3/4 inch, not where they should be but getting there.
 
tiriaq said:
Don't know if it is just the photo, but the boltface looks really horrible - rough, textured. The edge of the firing pin hole looks eroded. Lots of brass smearing. This was a brand new rifle, 200 rounds ago?
It would be worth contacting Remington, at least make them aware of the situation. If a gunsmith touches the bolt, you will definitely be on your own.
Click to expand...

X2
bigbull
 
You must log in or register to reply here.
Back
Top Bottom