Bolt, buffer, and springs......

[MikieM]

Well, here I sit having dinner. On the menu is roasted Crow. It's not all that tasty, but what the hell, I deserve it. 

Just my way of saying that Flatland Shooter, L9X25, Patrick Scott, and others, all know what they are talking about when it comes to recoil and the PCC.

In my own defense, however, I usually like to take the long way around the barn on things and this subject was no exception. How else can I learn anything?

 

I took a gun to the range today with a hundred rounds of ammo loaded with 4 grains of VN320 under 124 grain jacketed RN's. The gun was my QC10 upper/lower with the Ubl ULW barrel. It weighs about 5 and 1/2 pounds depending upon the bolt and buffer. In the gun was a Taccom bolt (14.5 ounces) and a 7.5 ounce Spike's buffer. Spring was a Sprinco "blue" enhanced power. I also took along a 6 ounce buffer, and a Sprinco "white" standard carbine spring.

My goal was to ascertain how much dot movement occured with each combination. Here are the results.

1. 7.5 ounce buffer with the "blue" enhanced power spring. A little dot wiggle, but not much. Acceptable.

2. 7.5 ounce buffer with "white" standard carbine spring. Only slightly more wiggle. Still acceptable. 

3. 6 ounce buffer with "blue" enhanced power spring. Better, but a very small amount of dot movement. Very acceptable.

4. 6 once buffer with "white" standard carbine spring. Hardly any movement. With a strong hold and shoulder mount, dot movement disappeared.

Urethra! The gun is ready to compete. 

 

In conclusion, let me just say that Orion's Hammer has very little to do with what we do and may be more beneficial in larger calibers. Having said that I must admit that I felt a very small amount of debris spit back at me today, but certainly nothing to worry about. I would imagine these light bolt/buffer combos are pushing the safety envelop a tiny bit, but if it works, it works.

I just now ordered a 4.5 ounce buffer and another standard carbine spring. I'm going to use it in the ULW (short barrel) and the 6 ounce buffer in the longer 10.5 inch barrel.

Thanks, Mike.

 

 

Edited February 19, 2018 by MikieM

[Garmil]

Interesting, what made you go away from the multiple piece buffers and use the standard ones for your final testing?

[muncie21]

Thanks for sharing your experiment Mikie. 

 

Looks like a pretty even comparison, any  'spacers' used with either buffer?

[MikieM]

6 minutes ago, Garmil said:

Interesting, what made you go away from the multiple piece buffers and use the standard ones for your final testing?

 

Simplicity, I suppose. There's nothing wrong with them, unless of course they fail, but to me all they do is add more stiffness to the spring that is already there. 

Just my opinion.

Edited February 19, 2018 by MikieM

[MikieM]

1 minute ago, muncie21 said:

Thanks for sharing your experiment Mikie. 

 

Looks like a pretty even comparison, any  'spacers' used with either buffer?

 

Nope. These two buffers were long enough to work fine.

[Aircooled6racer]

Hello: Now you just have to try a buffer in the 4.8-5.2oz range with a 223 spring. Also a 16" lightweight barrel with your 124's and 3.8 N320 or 3.1gr of Tite Group. Thanks, Eric

[MikieM]

Thanks, Eric. I should have added your name to the list, too.

I have a 4.5 ounce buffer coming. Should show up Wednesday. 

[Aircooled6racer]

1 hour ago, MikieM said:

Thanks, Eric. I should have added your name to the list, too.

I have a 4.5 ounce buffer coming. Should show up Wednesday. 

Hello: No problem. Since you have the different weight springs try the lightest one and see how it does with the 124's. You are close to my buffer weight that I am using and really liking right now. Thanks, Eric

[dlightning]

May I ask where did you order the buffer from? 

[MikieM]

27 minutes ago, dlightning said:

May I ask where did you order the buffer from? 

 

Primary Arms. They have a good selection in various weights.

[L9X25]

Mikie,

 

You are putting in the work and analyzing your own results.  That is the way to remain objective.

It is way too easy accept other people's results, without ascertaining how they reached those results.

 

Eric and I had the benefit of starting out with the JP SCS, that gave us the ability to add or subtract weight in 1oz 

increments, with a wide range of options.  We also had 8 spring weights to choose from and could mix and match

buffer weight and spring weight to see how it all felt together.  

 

Eric was first and reached his conclusions.  I did not follow his logic and went the opposite way with increasingly heavier

buffer weights, but the dot movement was worse the heavier the buffer got.  I started back the opposite direction and 

could see that the feel (but more importantly the hits) were getting better as the buffer got lighter.   I arrived at a similar

buffer weight and spring weight to what he did.    I took the long way around the barn myself. 

 

 

[Aircooled6racer]

Hello: Guys playing around with PCC's is part of the fun for me. I did the same with my open pistols until I found what worked for me and also seems to work for others. I just posted what works for me and hopefully helps others along the way. Saying one setup is good for everyone is not true since we all like the rifle to react a certain way. I have shot some setups that guys are using that do very well with and think this is terrible but works for them. They have tried my setup and thought it could be better as well. Time behind the sights is a wonderful thing is what I found to be true for everyone. I like the full length stroke of the bolt when others like the shorter stroke. I find it easier on my shoulder(bad) and my hits are better with the longer stroke. Is it faster, it seems to be for me. for my testing I use a timer and also hits on paper. Gun feel just does not work for me since my mind says that feels really good and when I look at the timer and hits it proves me wrong. Lastly shooting style comes into play as well. If you can do really fast splits a different setup maybe better for you than someone who is a little slower. Shooting matches will be the final test to see what works best for you. Thanks, Eric

[MikieM]

Well said, the both of you. 

[Photon]

Post like this are what makes this a fantistic forum for us guys new to PCC

Thanks

[Garmil]

Thinking where the total weight comes from makes a difference? You're buying a 4.5 buffer to use with your 14.5 bolt but you could have just used the 7.5 buffer and taken out your 2.5 carrier weight and been real close to that without buying anything.

[MikieM]

6 minutes ago, Garmil said:

Thinking where the total weight comes from makes a difference? You're buying a 4.5 buffer to use with your 14.5 bolt but you could have just used the 7.5 buffer and taken out your 2.5 carrier weight and been real close to that without buying anything.

 

My God, man! Are you insane? Buying stuff is part of the experience.

[Aircooled6racer]

Hello: Or you could make the plug that goes in the bolt out of aluminum and also the weights for the JP SCS. Lots of options is a good thing. Thanks, Eric

[Flatland Shooter]

Now its time to buy another PCC and leave your match gun alone.  I've written down all the specs on my match gun should any parts need to be replaced in the future but other than a good cleaning after each match, I'm done playing with it.  It will stay as it is with no further modifications.

 

Experiment all you want with the second gun (that's half the fun) and maybe someday it will be even better than the first gun.  (Have you ever heard of better justification to buy another gun?)

 

 

[MikieM]

Funny you should mention it. I have a new one in the works and will post a picture in a couple of weeks. 

[Supertrunk]

Thank you for your thoughts, we conversed shortly on this. Each of us has different challenges and different solutions. Me, I don't have the time to reload, and am going to settle on one, widely available, commercial ammunition and tune to it. Some folks will be tuning to a specific bullet, or PF. LOTS of good information here, thanks for helping me learn!

[timawa]

Very extensive and good informations you made for the benefit of the PCC world. How about starting a “loan program for PCC parts” for other shooters to help out ease of the costs of buying new parts? 

[MikieM]

If you're talking to me, the only thing I have left is 2 Lead Star butt stocks.

 

As far as good information, it's a shared wealth. Each of us has something to give. Even the newest among us.

I hope that together we can make PCC the biggest and most exciting division in the USPSA. 

Edited February 20, 2018 by MikieM

[Aircooled6racer]

11 minutes ago, MikieM said:

If you're talking to me, the only thing I have left is 2 Lead Star butt stocks.

 

As far as good information, it's a shared wealth. Each of us has something to give. Even the newest among us.

I hope that together we can make PCC the biggest and most exciting division in the USPSA. 

Hello: I am just glad to see more people coming in and coming back to USPSA matches. Shooting PCC has a lot of the older guys coming back in since they can shoot something that has a dot and they don't have to reload for the stages. It also is a cost thing for some of the rifle shooters since they can shoot pistol calibers instead of rifle calibers. Young guys like it since they can shoot really fast and beat some of the old guys. I realize some don't like the PCC's at a pistol match, we have some around here like that so it also appeals to the rebel side for some as well. I know around here we get between 8-20 PCC's for every match. We have 20 signed up for this coming weekend, ranging in age from 20-70 something. Fun for all and all for fun. Thanks, Eric

[wgj3]

3 hours ago, MikieM said:

If you're talking to me, the only thing I have left is 2 Lead Star butt stocks.

 

As far as good information, it's a shared wealth. Each of us has something to give. Even the newest among us.

I hope that together we can make PCC the biggest and most exciting division in the USPSA. 

 

This^^^

 

And I also kinda want some solid Open GM to always win the faux HOA title so that nobody can complain that "those rifles just make it too easy to win the (nonexistent) HOA title"...

But I would be perfectly OK with PCC's taking positions 2-10 in the overall standings...if there were such a thing...

[dlightning]

So this has got me itching to experiment.  I have a 14.5 QC10 barrel and currently running the taccom bolt WITHOUT the weight using 124 gr Acme with 3.3 gr of Titegroup.  With the 3 stage taccom buffer assembly.

 

Dot movement is there but I don't know anything else.  If I followed Eric's suggestion then I should next use a 5 oz weight.  Along with a Spinco yellow or orange spring or JP polish carbine spring.?

 

Is this in the right direction?