Pressure signs from suppressor?

[5MilesBack]

Peterson brass typically has a little less capacity, 1.5-2 grains depending on case.

For my .243 I posted about above with 108gr ELDM's, I reloaded the pulled bullets from the UM ammo with Norma brass to 2.80" COAL, loaded back 41gr H4350, and they averaged 2972fps. I also loaded new virgin Lapua brass the same.......CCI200's, 41gr H4350, and 108 ELDM's at 2.80", and those averaged right around 2850fps. It's always a crapshoot when using different brass. But I'll eventually narrow down to whatever brass I'm using and they'll be consistent, hopefully with speeds and pressures. The original UM loads had 42.7gr of H4350 and loaded to 2.71". So fairly hot load.

I have some virgin Peterson brass for my 6cm that I'm going to be loading at some point here. I'll adjust starting loads accordingly now.

 

[JF_Idaho]

Longer barrels do not increase chamber pressure.

You're right. They just increase pressure. Peak pressure is not equal to pressure.

 

[Lawnboi]

If there really was more pressure you would likely see a velocity increase as well.

The case is supposed to grab the chamber walls. When there is moisture lube, whatever in there keeping that from happening it seems the case gets smashed into the bolt face.

Iv chased this a few times. Now if I’m shooting in the winter I shoot my string quickly, and use a fan to keep smoke out of my chamber and out the muzzle.

That’s the only explanation I have found. I load farily low and have seen unexplainable pressure signs as well, almost always on cold days with moisture and a headwind.

I’d also agree that you are likely a little hot with Peterson brass . I have also seen h4350 vary in velocity depending on the lot.

 

[WoolyBugger]

If there really was more pressure you would likely see a velocity increase as well.

The case is supposed to grab the chamber walls. When there is moisture lube, whatever in there keeping that from happening it seems the case gets smashed into the bolt face.

Iv chased this a few times. Now if I’m shooting in the winter I shoot my string quickly, and use a fan to keep smoke out of my chamber and out the muzzle.

That’s the only explanation I have found. I load farily low and have seen unexplainable pressure signs as well, almost always on cold days with moisture and a headwind.

I’d also agree that you are likely a little hot with Peterson brass . I have also seen h4350 vary in velocity depending on the lot.

Seems plausible..

I would just think if it was purely over pressure, I would have sticky bolt lift on my very first shot of my rounds loaded for power factor. Or at least not be able to run through a string of 10 without sticking the bolt once.

 

[mt100gr.]

Hornady ammo has been extremely inconsistent the last few years. I have had back to back lots of 80gr ELD-M be over 100fps MV different, including way into pressure.

Copy that. I've seen where you've mentioned that recently. I bought a couple boxes to see if it'd give me a hint as to what bullet it likes and then plan to handload. Both 80s look promising for a first 10rd group, so thats back burner now. I'm really hoping that it shoots the 88 Ms )or the 88TMK if I can get my grubby hands on some)

 

[wind gypsy]

Shooting into a headwind in MN winter suppressed = pressure signs for me. It’s not a handloads issue, it happens with all factory ammo as well. Less so with 223 but with 6 and 6.5 creed for sure.

Good news is I don’t have these issues when spring rolls around and match season starts.

 

[Deadwood]

I just got my first suppressor (Unknown Reaper) and went out to rezero with my same hand loads I’ve been using the past 900 or so rounds on my gun, felt a slightly sticky bolt towards the end of the 10 round zero. After this I waited a couple min and went into a shooting drill and after a couple shots I started getting sticky bolt that progressed to heavy bolt lift and I stopped, ejector swipe on my brass.

Next day I went out to see if removing the can when I started to get sticky bolt lift would remedy this. I shot a 10 round string, waited approx 2 min then started another string. After 3 shots on the second string I had a slightly sticky bolt, next shot was very sticky. Removed the can instantly and quickly fired 2 shots, no hard bolt lift no ejector swipes on those 2 rounds

I’m not shooting a particularly hot load in my opinion. 6.5cm 140gr eldm 41.5gr h4350 Peterson brass. I’ve never noticed ejector swipe and have never had an even slightly sticky bolt.

Is this common? Is there a reason why the design of the reaper would have this happen over a different kind of can? Again this is my first one so I have nothing to compare it to and I’m fine putting this on a hunting rifle that won’t go through long strings but I will be using this particular gun for NRL and prs this summer. I would lighten the load but I’m just at power factor minimum for nrl so I’ll just put a brake back on if I have to.

I have noticed this with various brands of cans. Usually starts around 10 shots when its warmed up good. I Backed my load off half a grain and it went away. I cant explain why, but it is a known phenomenon. Someone smarter than me can probably explain why a hot can does this in some instances.