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This all relates to the rifle that was involved in this incident a few months ago:

https://www.24hourcampfire.com/ubbt...-some-bad-r-p-6mm-rem-ammo-#Post14297300

I think the incident was due to old ammo improperly stored. Had I known the full story from the beginning I would never have originated that thread, but the guys who were asking questions weren't forthcoming with the facts.

Anyway, the owner of the rifle tried some different ammo per my recommendation. This would be the very first time the rifle has been fired since the primer disintegration incident. He asked me to check out his rifle because he's experiencing hard bolt lift and he's afraid that the rifle has been damaged.

I have the rifle. I looked at the bore and chamber and took the bolt apart to see if there was any debris from the shattered primer cups in there. I found nothing, and the riveted extractor moves very freely. The ejector plunger is not binding and resistance to movement seems about right. I lubed the threads and lugs of the bolt and put the bolt back in the rifle.

In his rifle case I found the box of ammo he was shooting, it is Federal Premium Vital Shock 6mm Rem 100 grain Partition catalog number P6C. The price tag on the box is 34.99, so it's not REALLY old ammo, but it is in the red and black box. Lot number appears to be Q5 X736.

I found that an unfired cartridge chambers readily and the bolt closes with ease. There are four fired cases in the box and I found that it takes unusual effort to close the bolt on them, and it just does not seem right to me. I have two 788s of my own, one in .222 and another in .223, and I have not noticed this happening. I had another 788 in 6mm briefly myself and shot handloads in it, and I don't recall it behaving this way either.

So, is this indicative of an issue with the rifle, or is it indicative of soft brass (which I think Federal has been noted for in the past). I'd sure appreciate some educated input here before I tell my friend what I think. The guy has the attention span of a jackrabbit and can be difficult to communicate with, so I'd like to be able to give him a definitive answer if possible. Thanks in advance.
I would get at set of go no go gauges and see if it is head spaced right. If so then try a different brand batch of ammo.
I think that's a good idea, but I'm a little puzzled with how tightly a fired case fits the chamber. It suggests some "sponginess" in the action, maybe. I just don't know about that. But I suppose it could be the ammo, too.

I think Ill measure the shoulders of fired cases and unfired cartridges. Maybe that would shed some light on this.
While I have not seen it myself, there was some talk when the 788 was new that the rear locking lugs could allow more brass stretch than a front lug action. Also, it is more difficult to get all of the small locking lugs to seat properly than a two lug bolt. A few will carry all of the thrust while the rest don't touch.
Like all rearlocking actions, there is some compression of the bolt and stretch of the receiver. The higher the pressure, the more stretch there is. GD
Used a 788 243 for years>20 without a problem. Likely 90% of the rounds fired were handloads.
Kept a no go gage on hand per recommendation of a gentleman I have great respect for and the rifle never
got out of spec.
it's the ammo
Originally Posted by greydog
Like all rearlocking actions, there is some compression of the bolt and stretch of the receiver. The higher the pressure, the more stretch there is. GD



can you point me to where you heard this. would like to read about it, 788 action stretch? isn't a mark 5 acton a rear lug locking bolt and all there cartridges are very high pressure.
Measurements indicate that the Federal factory brass last shot in the rifle (4 rounds worth) stretched in the body by eight or nine thousandths.

His factory Federal ammo chambers easily in my own Model Seven. I can't even begin to close the bolt of my Model Seven on an empty case which was fired in his 788.

My own handloads chamber easily in his rifle. I was thinking I might fire one, but I will ask his permission before I do so. My handloads are not particularly hot and are in fact pretty middle of the road, but if something bad happens I do not want it to be the result of my having done something without his approval. Maybe I'll get a hold of him and then pop one off out in the backyard.
I might fire one of his factory loads in my own rifle, for that matter. More data is better!
If it was mine i would check it with some other ammo.

I had one in 223 and it had with some really bad loads,brass that would not fit.

I believe that it is not the receiver that stretches it's the bolt that compresses.

Just like the Savage 99 does.

They are good rifles but can be quirky sometimes.
Originally Posted by gemby58
Originally Posted by greydog
Like all rearlocking actions, there is some compression of the bolt and stretch of the receiver. The higher the pressure, the more stretch there is. GD



can you point me to where you heard this. would like to read about it, 788 action stretch? isn't a mark 5 acton a rear lug locking bolt and all there cartridges are very high pressure.


The Mark 5 has multiple locking lugs but it is a front locking action. Bolt compression seems to be the culprit.
anyone that buys the idea of a bolt compressing is an idiot it aint gonna happen dumb asses..
Originally Posted by wtroger
I would get at set of go no go gauges and see if it is head spaced right. If so then try a different brand batch of ammo.


Still this.
Originally Posted by 257heaven
Originally Posted by wtroger
I would get at set of go no go gauges and see if it is head spaced right. If so then try a different brand batch of ammo.


Still this.



+1 Make sure the chamber is right, and then start looking at your lots of ammo, and if they are reloads look there...

ALSO ... check the bolt face, and chamber for gunk and debris... even a flake of powder can cause more problems than a guy thinks they will.
Originally Posted by Kp321
Originally Posted by gemby58
Originally Posted by greydog
Like all rearlocking actions, there is some compression of the bolt and stretch of the receiver. The higher the pressure, the more stretch there is. GD



can you point me to where you heard this. would like to read about it, 788 action stretch? isn't a mark 5 acton a rear lug locking bolt and all there cartridges are very high pressure.


The Mark 5 has multiple locking lugs but it is a front locking action. Bolt compression seems to be the culprit.



that came out wrong when I typed it I was referring to the multi small lugs. saying rear locking lugs causes bolt compression and action stretching is far left. that's like saying a 1 piece base stiffen the action
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