Dirty barrel and sd relations ?

[swd]

Since you bumped the load and got the speed back take the suppressor off and see if it groups again.

 

[DLT]

Since you bumped the load and got the speed back take the suppressor off and see if it groups again.

I will sir. To get that speed it was almost 1 whole grain of powder to get it back

 

[swd]

I will sir. To get that speed it was almost 1 whole grain of powder to get it back

Also if you have been checking the speed with the suppressor on, check it again with it off. Re adjust the load for the speed again if needed. Then check the groups.

 

[DLT]

Also if you have been checking the speed with the suppressor on, check it again with it off. Re adjust the load for the speed again if needed. Then check the groups.

That’s what I was going to ask. I can get the speed up but sd was pitiful. Groups wasn’t bad just not like they were

 

[RabbitSlayer]

I live where it is super dry. Even if it is the same lot it is slower when I first open a can and then gets faster as it dries out. Thought I was crazy at first, but happened a bunch of times now. Fclass john posted a really good article on the subject. It had some very in depth testing, but the summary is humidity and moisture content of the powder can make a very big difference.

 

[Fast14riot]

I’ve seen video from Keith Glasscock using humidor packs and desiccant packs to experiment with humidity levels in powder. Winning in the wind on YouTube, check it out. Maybe desiccant packs in a one pound container would help. I would definitely clean the barrel and test seating depth again though.

The packs he uses are two way humidity control packs. They will raise or lower the humidity according to the percentage packet you use. Boveda is one brand. You can get 62%RH packs and they will keep your powder to 62% if above or below that. They have other % packs too.

 

[Ringostar]

Maybe it was the article that F Class John linked, were the guy also used desiccant to really bring the moisture down. I’m thinking of experimenting when I get my 7 saum barrel back from chambering. A friend has done very well with RL23 in a saum, but you can’t find it. I have N560 and N565 which are above and below that. I live in very low humidity, so I will try drying or should say speeding up some N565.

 

[searcher]

I check the velocity on my varmint loads about every 1,000 to 1,200 rounds or so before loading up a large batch of ammo (usually about 1,000 rounds) for another varmint session. I know I'm going to encounter velocity loss from my last batch, so I check to see how much powder I need to up it to my desired velocity again and check on target that it is still a good load. I typically see about 50 FPS drop just due to barrel wear every 1,000 rounds +/-. On a barrel with 3,000 rounds - my total velocity loss (in .20P and .223 loads) is typically about 130 FPS with the loads I shoot, so I'd not just write that off as a change in powder. I typically use the same lot through the life of the barrel. Humidity changes and other factors do come into play, but you can definitely expect some velocity loss just due to wear..

 

[DLT]

Also if you have been checking the speed with the suppressor on, check it again with it off. Re adjust the load for the speed again if needed. Then check the groups.

Ok so I took my suppressor off the rifle and the sd/es dropped as in back as good as they used to be. Groups about the same but still low fps. I bumped the charge up and things still remained good with the suppressor off. I cleaned it again and bore scoped it and boy was it a shock. Big time fire cracking for 5-6” in front of the throat . I guess that would have a bearing on my speed and accuracy.

 

[swd]

Ok so I took my suppressor off the rifle and the sd/es dropped as in back as good as they used to be. Groups about the same but still low fps. I bumped the charge up and things still remained good with the suppressor off. I cleaned it again and bore scoped it and boy was it a shock. Big time fire cracking for 5-6” in front of the throat . I guess that would have a bearing on my speed and accuracy.

At 800sih rounds I expect a fair amount of fire cracking. They can still shoot really well with fire cracking. Around 800 I tend to see some carbon build up if I haven’t stayed on top of it as well as I should have. If you haven’t already I’d give it a good cleaning with JB, Thoro Clean or your favorite flavor of abrasive bore cleaner. Then I’d do a little more tuning and see if it comes back. If not it might just be one of those barrels that gave up sooner than later. Sometimes it’s hard to know when to give up on a barrel that you would think is only mid life.

 

[DLT]

At 800sih rounds I expect a fair amount of fire cracking. They can still shoot really well with fire cracking. Around 800 I tend to see some carbon build up if I haven’t stayed on top of it as well as I should have. If you haven’t already I’d give it a good cleaning with JB, Thoro Clean or your favorite flavor of abrasive bore cleaner. Then I’d do a little more tuning and see if it comes back. If not it might just be one of those barrels that gave up sooner than later. Sometimes it’s hard to know when to give up on a barrel that you would think is only mid life.

I did. I give it a good iosso scrub job I’m thinking it’s closer to 1000 rounds

 

[ArtinNC]

A suppressor will extend the harmonics on a barrel as well as speed up the muzzle fps. Not exactly starting from square one with load dev, but the load will need to change.

l as well as speed up the muzzle fps. How is that ?

 

[David Christian]

l as well as speed up the muzzle fps. How is that ?

Longer effective barrel, more bullet time along the length. Same effect as going from a 24” barrel to a 30” barrel using the same load.

 

[ArtinNC]

"""A suppressor will extend the harmonics on a barrel as well as speed up the muzzle fps."""Will Speed up muzzle fpc . I don't think so , I don't see how that could be .

 

[DLT]

It

l as well as speed up the muzzle fps. How is that ?

It didn’t speed up my rifle. It did however double my s/d with it installed