Buffer Testing

[Racinready300ex]

I like to tinker to much for this division lol. I'm in trouble.

[R1valdez]

18 hours ago, Racinready300ex said:

 

It shot good but I didn't really like how it felt. It was not one of the setups in this test. The one I'm leaning toward is the Scheel delayed buffer. Still allot I can do with it too fine tune.

So which buffer is T?

[Racinready300ex]

13 minutes ago, R1valdez said:

So which buffer is T?

 

It's the taccom adjustable buffer with the short stroke bumper. When I originally shot these I didn't plan on starting this thread. Perhaps I'll update it as I continue to test setups, maybe the info will be useful. Anyway the minimal difference in results here have a considerable cost difference. I also had some initial trouble with the Scheel buffer which I think I've worked out by switching to a JP bolt. I'm assuming just my combination of parts didn't like each other.

 

The JP bolt doesn't really pair well with the Taccom Delayed buffer which might be a better comparison to the Scheel. 

 

Next trip to the range I'll do the same test with the Scheel but this time running about a 16mm shorter (5/8") stroke and increasing the tension on the rollers with a additional spring. I think this stroke will be more similar to the Taccom, maybe even still just a touch longer. I can still manually engage the bolt hold open, if that gives you a idea of the length of the stroke. 

[R1valdez]

3 hours ago, Racinready300ex said:

 

It's the taccom adjustable buffer with the short stroke bumper. When I originally shot these I didn't plan on starting this thread. Perhaps I'll update it as I continue to test setups, maybe the info will be useful. Anyway the minimal difference in results here have a considerable cost difference. I also had some initial trouble with the Scheel buffer which I think I've worked out by switching to a JP bolt. I'm assuming just my combination of parts didn't like each other.

 

The JP bolt doesn't really pair well with the Taccom Delayed buffer which might be a better comparison to the Scheel. 

 

Next trip to the range I'll do the same test with the Scheel but this time running about a 16mm shorter (5/8") stroke and increasing the tension on the rollers with a additional spring. I think this stroke will be more similar to the Taccom, maybe even still just a touch longer. I can still manually engage the bolt hold open, if that gives you a idea of the length of the stroke. 

I've tried that JP bolt Taccom delayed buffer combo which resulted in a burst fire with hyperfire trigger combo. I didn't really like the sharp recoil it gave. I'm using the Taccom adjustable buffer at the moment.

 

[WxGuy]

Tuning buffers and springs is a really fun time.  I ended up going the A5 rifle tube route with a Blitz 5006 buffer and JP 308 rifle spring.  I like it so much that the other 2 lowers I have sport the exact same setup.  I like reading about all the different combos but the A5 rig is my one and only choice.  Thanks Max!!

[Racinready300ex]

Went to the range yesterday and shot this group. Same as last time, doubles @ 20 yards splits about 19, this time with the Scheel buffer and a shorter stroke plus a slight tweak to the springs. This seems to be slightly better than last time. 

[Racinready300ex]

Now this target was the exact same setup I just changed me a little. I held the gun looser, and up higher on my shoulder (to high probably). Trying to let the gun just do it's thing a little more, kind of like if I was in a match and didn't get everything right in a position. The dot moved around more, but I think I got better as I went. Obviously I had a few wild shots. But the big change was while more relaxed I could run about .15 splits. To me that's a significant change in split time and minus the two wild shots a group that's not a bad group.

 

So this gives me some ideas on how to change what I'm doing to hopefully get faster, primarily relaxing. If I can tighten this up just a bit and hold 14-15 splits at this distance I think I'll be on the right track. I'm not exactly sure what's good enough but it seems like there is more on the table. 

[R1valdez]

32 minutes ago, Racinready300ex said:

Went to the range yesterday and shot this group. Same as last time, doubles @ 20 yards splits about 19, this time with the Scheel buffer and a shorter stroke plus a slight tweak to the springs. This seems to be slightly better than last time. 

What’s your spring configuration  on the Scheel buffer? I’m going to try weak in 1 and strong in 2 and 3 slot

Edited September 7, 2021 by R1valdez

[Racinready300ex]

16 minutes ago, R1valdez said:

What’s your spring configuration  on the Scheel buffer? I’m going to try weak in 1 and strong in 2 and 3 slot

 

The main spring is the Blue, Then I started with light then heavy as he recommended. This time I just added another light spring in the next hole. The bumper I'm running to shorten the stroke 40mm so about 1.5-1.6" 

[Racinready300ex]

Stopped at the range last night to test a new load. I've been shooting my CO load of 135 gr TC bullets about about 140 PF. Once these are gone I planned to switch to something more PCC specific. This target is 115 gr RN at 132 PF everything else the same as my last test. I immediately noticed the first round chambered smoother, so I'm hoping these round nose bullets will be more reliable. Not that I'm having any real reliability issues at this point. I'll probably use this gun in some IDPA matches so I'll need to bump the PF up closer to 140. (IDPA PCC needs 135 PF)

 

Anyway this is the target from today. Again it's doubles at 20 yards, I think the splits were about 16-17 but my timer was acting funny. This seems like a pretty solid result. 

[Fasthenk65]

4 hours ago, Racinready300ex said:

Stopped at the range last night to test a new load. I've been shooting my CO load of 135 gr TC bullets about about 140 PF. Once these are gone I planned to switch to something more PCC specific. This target is 115 gr RN at 132 PF everything else the same as my last test. I immediately noticed the first round chambered smoother, so I'm hoping these round nose bullets will be more reliable. Not that I'm having any real reliability issues at this point. I'll probably use this gun in some IDPA matches so I'll need to bump the PF up closer to 140. (IDPA PCC needs 135 PF)

 

Anyway this is the target from today. Again it's doubles at 20 yards, I think the splits were about 16-17 but my timer was acting funny. This seems like a pretty solid result. 

very nice!  With what powder?

[Racinready300ex]

5 minutes ago, Fasthenk65 said:

very nice!  With what powder?

 

Clean shot.

[Fasthenk65]

2 minutes ago, Racinready300ex said:

 

Clean shot.

Tnx let me guess 4,4 grain with 115's to achieve PF135?

[Racinready300ex]

1 minute ago, Fasthenk65 said:

Tnx let me guess 4,4 grain with 115's to achieve PF135?

 

I'll have to check when I get home. I was set up for 135 gr bullets making 135 PF out of a CZ. I didn't really change much just switched the bullet, this is in a 13" barrel. I'd guess it's like 3.8 but I can't remember. 

[Fasthenk65]

Just now, Racinready300ex said:

 

I'll have to check when I get home. I was set up for 135 gr bullets making 135 PF out of a CZ. I didn't really change much just switched the bullet, this is in a 13" barrel. I'd guess it's like 3.8 but I can't remember. 

then for sure you have to chrono  guess you are at 123 PF or so now

[Racinready300ex]

54 minutes ago, Fasthenk65 said:

then for sure you have to chrono  guess you are at 123 PF or so now

 

First thing I did was chrono, it was at 1150-1160 fps. Maybe the powder drop is dumping more than I remember or my chrono could be off.

 

 

[AKJD]

5 hours ago, Racinready300ex said:

 

First thing I did was chrono, it was at 1150-1160 fps. Maybe the powder drop is dumping more than I remember or my chrono could be off.

 

 

I run a Brekkecustom 16 inch barrel of which 4 inches is compensator and get an average velocity of 1175 with Berry 115 for a power factor of 135 with 3.9 grains of Clean Shot.

[RaylanGivens]

Are you guys having any luck finding Clean Shot?

 

I'm about out...  Been looking for it for quite while...  Good stuff...

[Racinready300ex]

I have not seen any clean shot in a while.

 

I checked my charge I was sitting at 3.7, I just bumped it up to 3.9 I'll retest probably next week.

[Fasthenk65]

15 hours ago, AKJD said:

I run a Brekkecustom 16 inch barrel of which 4 inches is compensator and get an average velocity of 1175 with Berry 115 for a power factor of 135 with 3.9 grains of Clean Shot.

Maybe the barrel of a JP15 is very slow? I need 4,4 to come close to 130... (Lovex D032 which is the same as cleanshot)

[AKJD]

15 hours ago, RaylanGivens said:

Are you guys having any luck finding Clean Shot?

 

I'm about out...  Been looking for it for quite while...  Good stuff...

I get it from 49th Cartridge Company here in Fairbanks Alaska who is a distributor and he was told directly from Shooters World that it is in short supply. 

 

I'm not an expert on these things but from what I understand there is a shortage of nitrocellulose for manufacturing gunpowder.

[LowSpeedHighDrag]

On 9/10/2021 at 11:06 AM, Fasthenk65 said:

Maybe the barrel of a JP15 is very slow? I need 4,4 to come close to 130... (Lovex D032 which is the same as cleanshot)

I have a GMR13, and the barrel consistently produces lower velocities than other barrels (Taccom , etc.).  AFAIK the barrel is noticeably tighter than the others.

[Ner]

On 9/10/2021 at 6:06 PM, Fasthenk65 said:

Maybe the barrel of a JP15 is very slow? I need 4,4 to come close to 130... (Lovex D032 which is the same as cleanshot)

with 4.1 D032 * 115gn i got ~132-135

4.45 D032 gave me about 138-140

at what Coal u load? 

[Fasthenk65]

6 hours ago, Ner said:

with 4.1 D032 * 115gn i got ~132-135

4.45 D032 gave me about 138-140

at what Coal u load? 

1130 so 28,7 mm....