Gunboards Forums banner
1 - 17 of 17 Posts

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #1 · (Edited)


Ok so I loaded three 7mm-08 rounds with:

154 SST Hornady
39.2 of IMR 4064
Remington No. 9 primers
COAL is 2.795
Very light if any crimp.
Load is smack dead on and in the middle of the IMR min./max. for this round and powder.

The grouping is 1.43" center to center at approximately 55 yards.

Not sure what to think of the primers with the pronounced ring around the fp dimple. Shots were about 1 minute apart. Temp. 65 with slight 1o'clock gusts of wind.

Thoughts on the primers?

I plan on going with 40.5grs next which splits the middle with the top.
 

·
Administrator
Joined
·
10,116 Posts
Primer Metal is setting Back into an over-sized Firing Pin Hole in the Bolt. This is also a Pressure Sign, that you are getting close to Higher Pressures in your Loads. IN any case, either the FP is undersized, or the FP Hole is over sized...is your rifle a Converted Milsurp, or a Factory Commercial Sporter?...

Don' go Higher in Powder Load until you rectify the current Pressure Problem.

Doc AV
 

·
Registered
Joined
·
601 Posts
If you bought it from a dealer, show him the fired cases and ask to have the rifle sent back to Remington for service. Check your loaded rounds to insure that the bullet is NOT touching the rifling when chambered. Does a round drop completely into the chamber without resistance or do you feel any "compression" type resistance as you close the bolt? DocAV is correct. It's a pressure sign that can be caused by a number of factors. Have it checked. Also, did you mean Remington 9 1/2 primers?
 

·
Registered
Joined
·
1,593 Posts
Pilot1950, the first question from that dealer is going to be......... "Are these cartridges new, factory ammo"? He's not going to send that rifle back based on someone's reloads.
Reloads showing that symptom is a red flag right out of the gate.
 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #6 ·
I measured some of those factory loads (Federal Power-shok 150 sp) and they measured 2.52, 2.57, 2.62" COAL. That is quite a variation and .018 - .027" longer than the reloads.

Yep, Rem 9 1/2 primers, sorry.

I think that this a.m. sometime I will fire a few factory federal rounds and compare the primers.

Prior to any case resizing and after cleaning the factory rounds, I did manually insert a bullet into a fired case and it dragged while inserting. It also stayed put while being held upside down. I just did the same thing and these 3 cases all would allow the bullet to drop right into the case. This makes me wonder if my reloads are actually hotter than factory (factory box shows 2650 muzzle velocity). Crunching the numbers with my reloads and stated velocities with that cartridge build, I should have a muzzle velocity of 2545. I know there are variables but I would think the first thing to check would be the bullet to land gap. I think I will shoot 3 factory loads and then the same reload seated to 2.62...unless you guys think that it would compress too much? I'll definitely check the primers on the 3 factory loads first though.
 

·
Registered
Joined
·
1,593 Posts
Kursk, I think you're relying too much on what the guys think. I suggest that you not drop in between load data, but begin from the bottom up in 1/2gr increments. Later you might even be weighing cases and projectiles.
Your rifle is not going to be a dead match for anyone elses anyway.
I mostly reload for Swiss 7.5x55 and AR10's, and after all this time I have specific formulas for load data development. If the rifle is capable, you'll later on find out how important those seat depths are by increments of pressure changes. Fine tuning an idividual rifle is really a satisfying thing when the end results are minor but show themselves in POI. I don't know how advanced you are, but start at the bottom, read carefully and begin one solid step at a time and eliminate all variables in your process.

Edited to add: Do you have that all-important Chronograph?
 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #8 · (Edited)
Well, I was weighing cases for the heck of it and there definitely is a difference between them.

Here are two empties from factory fed 150sp. Looks like the same exact primer sign stated above by Doc.



Does it constitute a call to Remington?
 

·
Registered
Joined
·
14,254 Posts
Kursk
Your primer indents may or may not be sign of high pressure.
Have you done anything like mess with the firing pin spring or replace it with a heavier spring?

Here is what I would check out.

1. Look at factory ammo fired primers and compare. If they look the same it is a rifle problem.
2. Get a good micrometer. Look at the pressure ring where the solid head of the case transitions to the case body walls. Compare with factory ammo. Where you see the largest bulge, measure factory and reloads and compare. The larger the bulge the higher the pressure assuming you are using similar brass. With most of my rifles I can tell that pressure is too high by looking at the pressure ring. When that transition is very sharp and starts taking on the appearance of a sharp step, the pressure is too high for that brass. The pressure may be ok according to SAAMI but large chamber combines with small case heads can combine to make a sharp step at the transition. When you see that you are damaging your brass.

3. Remove the firing pin assy out of the bolt body and look for excessive grease or metal particles left over from machining. Clean out the interior of the bolt with light oil and blow it out with compressed air. Wipe off the firing pin assy and blow any gunk out of the spring coils. Re-assemble and dry fire a few times. After re-assembly turn the cocking piece down off of the cocked notch. Then look at the firing pin protruding through the bolt face. The firing pin should not have much room to wiggle around. If the gap between the firing pin and firing pin hole is more than the thickness of a sheet of paper it may have too large a firing pin hole or too small a firing pin tip. S sheet of paper is about .003 thick. If you see twice the thickness of a sheet of paper I would be concerned.
4. Check your rifle again with factory loads. If you still get those extruded primers you have a weak firing pin or something else wrong with the rifle. Be prepared to discuss with the factory using fired factory ammo as proof.
5. Make sure you are not pushing the shoulder back creating excess headspace with the reloaded cases. In a Remington 700 you have that plunger ejector pushing the case forward all the time. If you have any significant longitudinal clearance between the length of the chamber and and ammo datum lengths, the 700 will push the case forward. This helps the primers back out and/or extrude.

As one that has used a lot of once fired brass from indoor ranges I have seen a lot of extruded primers with factory ammo. Most of the time it appears to be a rifle problem. The cases themselves are not expanded due to excessive pressure. I have seen this in every thing from 30-30 to magnums. When it is connected to a high pressure round the primer pocket is often expanded and the primer falls out of the case. If the primer does not fall out the case may still be damaged and you will find that a new primer does not seat with normal pressure.
 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #10 · (Edited)
Ok, I measured that area and here are the results:

reload: rp brass .4699, rem fc brass .4703, .4704
factory: fc brass .4686, fc brass .4690

I took the bolt apart as suggested, and clean it. Turned the cocking piece so the pin pushed through and used a dimple head finishing nail to try and move the pin. It did move slightly. I then took it apart again and the pin itself is .074 and couldn't get a reading of the hole with a caliper. So I tried to slip the pin through the outside of the face of the bolt with a .003 piece of paper and it would not go. I put the paper on one side of the hole and had to almost press fit the pin into the hole, but it did go. I don't think the paper had one side of the hole covered though.

Here are a couple photos of the bolt face. It looks dirty but it is not really.
 

·
Registered
Joined
·
14,254 Posts
Your loads do not appear to be excessive. I think it is your rifle.

Keep in mind that the reloads have been fired twice and the FL die probably does not squeeze them back to exactly the same size as the new unfired cases.
 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #12 ·
Next three cartridges loaded with 38.7 grains of IMR 4064 and the spent cases measure .4696, .4696, .4702". COAL is 2.787. Group size shrunk to 7/8" at 55 yards.

The primers are an issue it seems. They are still rounded on the shoulders though.

 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #14 ·
I'm calling Remington tomorrow as they were not open this evening. I think I can send it directly to them and the same in return. I suppose I'll have to take my scope off to fit in the original box.

I'm thinking that this rifle doesn't like 154's so maybe I'll get some 139 Horner SST. Any thoughts on if the primer issue could actually be part of the grouping problem?
 

·
Registered
Joined
·
14,254 Posts
I suspect your mainspring is weak.
If you have another 700 with the same bolt they might interchange and head space properly for test firing.

I expanded primer pockets about .020 oversize in a 1891 Mauser with lighter than starting loads.
I had two rifles. One rifle shot normally the other blew the primers. It made no sense since the cases were also sooted on the outside.
One of the rifles was new to me. That was it's first trip to the range. I noticed it's firing pin fall was slow and muffled. I swapped bolts with the two rifles and the rifle that blew the primers fired normally. I took the bolt apart at the range and found it packed with a lot of cosmoline. I spent 10 minutes cleaning the spring coils and the interior of the bolt. When reassembled and fired, everything worked fine. When I finished working up loads I was using charges 3 grains heavier than the ones that blew the primers.

Remington will not do anything for you if you tell them your extruded primers are from hand loads.
Do not even mention hand loads. If you have factory ammo shoot a few and send those along.
 

·
Registered
Joined
·
4,717 Posts
Discussion Starter · #16 ·
Thanks, Ireload. I shot some factory today and posted and the primers looked the same as the reloads. I'll call in the a.m. but I doubt they would send a new bolt because it may not headspace correctly unless they have gauges they can send along with a new bolt. Thoughts?
 

·
Registered
Joined
·
14,254 Posts
They will want your entire rifle. If it is the main spring they will just swap out the firing pin assy. If they are lazy they might put a complete new bolt in it and call it good. I needed a bolt for a rifle project once and said I lost mine. They wanted the rifle so they could make sure the head space was right. Make sure they agree to test fire it before sending it back.

Thanks, Ireload. I shot some factory today and posted and the primers looked the same as the reloads. I'll call in the a.m. but I doubt they would send a new bolt because it may not headspace correctly unless they have gauges they can send along with a new bolt. Thoughts?
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top