doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com A pressure problem or something else?

I would not expect bullet seating depth to have that much effect on chamber pressures. Bullet depth and crimp can indeed increase pressures a bit, but unless the loads are reaching maximum spec for the cartridge, it wont have that result.
I'd be getting out my bullet puller and pulling one cartridge apart on both the Federal and the Remington, and do a visual examination of the powder, plus measure the charges for both, just as a comparison. If it was an isolated incident, then an over charge wont show in an inspection, but I'd still do it to answer my own curiosity. By reverse engineering the charge based on weight, and info Federal provided on fps of their ammo, you might see something that you wont know without dissecting the components.

It's just a thought, but if you're satisfied that there are no unusual pressure signs, I don't know if a cast would tell much more than the fired cases already do. If it were me, I'd try not to push the shoulder back much when sizing, but it has the look like the neck is going to get worked a good bit. Maybe it wouldn't be too bad a thought to anneal the neck area and watch case lengths a bit more than average reloading.

I have had great results from JES. I had a bad barrel on a martini cadet someone screwed up befor JES got a hold of it .. When I discovered the problem and was sure it was not his fault I found another barrel (luckily) and sent the gun to him with a check for the new work. He did the new barrel in .357 maximum as I wanted and the chambered the barrel with the bad chamber in 35 herrett for no charge. An honest, fast turnaround craftsman

Jerry

Some more info for anyone interested...

I had posted this over on the Accurate Reloading forums and from there was made aware of a member having similar pressure problems with a .35 Whelen, rebored by JES in 3 groove, 1-14 twist like mine. JES states his .35 rebores are .349 bore, .359 groove.

Someone suggested it might be a tight bore so I slugged mine and came out with the quick sketch you see below. Notice it's not drawn to scale and I was able to get a caliper reading across a land and a groove.





It's 3 groove rifling so each land has a groove opposite, each taking up about 60 degrees of the circumference. I was able to measure the slug at 3 locations, all came out to .349.

Am I correct that to get the groove diameter (which should equal bullet diameter) I would add .004 (assuming average groove depth of .005) and arrive with .354?

This is .005 less than bullet diameter of .358.

I measured the Federal bullets and they are indeed .358. Interestingly enough the Remington Corelokts measure .356.

I am waiting on a call back from JES to see if I have made a mistake, the idea of 3 groove, not having lands or grooves opposite each other, is a bit perplexing.

Interested to hear thoughts from this community.

N.B. I just spoke with Jesse at JES, he told me my method of measuring is incorrect. he starts with a .349 hole and then rifles .005 deep for a groove depth of .359.

He thinks it may have been the Federal ammo and is going to get some to test.


thanks,

Rob

Can you measure this instead, and then do the math? I think an odd number of grooves is perfectly fine.

N.B. I just spoke with Jesse at JES, he told me my method of measuring is incorrect. He starts with a .349 hole and then rifles .005 deep for a groove depth of .359.

He thinks it may have been the Federal ammo and is going to get some to test.

Then, I'd suppose you should be measuring .354" instead of .349" using your method? Since, JES is responding and looking in to it, maybe see if they would like you to mail them a slug? They would probably rather do their own slug, but it may give them ideas.

That's what I thought, I should be measuring .354.

JES is not going any further with it but to check the ammo.

Perhaps I don't understand the geometry involved but I'll pursue it further though and report back any findings.l

With three grooves, they should be 120 degrees apart. If the bore is 0.349, measuring as you show, between the center of the bottom of a groove and the land directly opposite it, should give 0.354, not 0.349, for a 0.005 deep groove. The measurement would have to be from one land to another to give 0.349. If the grooves each do not span more than 60 degrees, there will be locations, 90 degrees or so from the centers of the grooves, where lands will directly face each other. Measuring from one land to another here would give your measurement of 0.349.
With care in choosing your locations, you should be able to both measure from land to land and from bottom of groove to land.

This is exactly what I thought. The grooves and lands are each 60 degrees of the circumference so I am able to get an accurate reading across all three sets, .349.