308 build question parts

[Trochlea]

Recently purchased a M1 for my dad for fathers day/late birthday. Took him shooting and he loved it, but the recoil was a bit much. Age added on to 100% disability really limited his shooting. The guy next to us had an armalite Ar 10 of some variation and he let my dad shoot it. He loved the idea of the ar 10 platform but would prefer lighter recoil, and asked me if i could build him one for around 1200. His priorities are low recoil then accuracy I have a build that will fit the bill using 6.5 creedmoor, as he was still worried about recoil. I'm at the upper limit of my budget and was not able to integrate either the jp recoil spring or low mass system. I am willing to go over budget out of pocket if they are going to appreciably reduce recoil. So my questions:

Do the jp recoil buffer/sping low mass carrier group appreciably reduce recoil? Could I replicate that reduction by simply turning down the gas block and minimizing gas return? Are there any other tip/ tricks with large frame ar's for minimizing felt recoil?

 

[mforsch]

A couple ideas come to mind--stemming from shooting 45 ACP target loads. The idea there was minimal recoil and slowed velocity, enabling more precise shots and faster recovery/sight acquisition after the shot (bullseye shooting). Not having an AR----I can't say with certainty that it can happen---but---a good AR gunsmith can provide a better answer. Heavier is better on the build, because more mass reacts less to recoil; lighter bullets and lighter loads produce less recoil-----the question is---can you build light handloads and have success by using a lighter buffer spring? (Follow where I'm going with this)? Any thing that alters gas pressure affects cycling and reliability--same as the 45---however 45's can be tuned to shoot bullets as slow as 650 FPS and still cycle properly by using special springs. Perhaps there are parts that allow light loads to be used. You might ask Jerry Miculek---he's a well known shooter--and has tons of experience with these types of things. Target guns get a lot of mods put on them. Good Luck.

The Springfields had a selector screw on the barrel port for the gas piston. Closing the port blocked gas flow to the piston and prevented the bolt from operating; the reason being is that maximum gas pressure was needed for ----Launching Grenades.
With that thought in mind---that same screw can be closed and the rifle fired with light handloads---the light loads will not have any effect on cycling, failure to clear on ejection or double stacking during extraction/ejection and feeding.
The drawback is--you have to manually cycle the bolt for the next shot.----It may---save Pop's shoulder and allow him to shoot "His" gun..

 

[Trochlea]

I thought about 300 black out but the He wanted to stick to the larger frame. I wonder how appreciable the switch to high weight bullets like these Woodleigh Bullets 264 Cal 6.5mm (264 Diameter) 160 Grain Protected would be on felt recoil? or whether they would even shoot in a 1:8 semiauto. May be worth a try

 

[banditbump]

Imo if u want less felt recoil u want lighter bullets. It's why they start off young hunters with 243 not 308...

 

[Lizardette]

An adjustable gas block can help when you're using light loads, which will of course reduce recoil. Don't discount the effectiveness of a good muzzle brake either. Beyond that, felt recoil can be minimized by having a stock that's properly fitted to the shooter. If you're planning on using an A1/A2 buttstock, Sierra Precision makes an affordable buttplate that's adjustable for length of pull, drop at heel, and cant.

SIERRA PRECISION AR-15 ADJUSTABLE BUTTPLATE | Brownells

If he wants a collapsible stock, it looks like Limb Saver makes a recoil pad that fits on "most" of them. They also make a collapsible stock that's supposed to reduce recoil. I don't know how well any of them work, but it's an option.

Tactical Page | LimbSaver - Products That Work

 

[DT1]

Muzzle breaks, adjustable gas blocks along with the JP Low mass carrier group and silent captured recoil spring will all help smooth out the recoil impulse on an AR10 and make the rifle easier to shoot. It would be a shame, however, to go to all that expense and effort only to discover it still has too much recoil for your Dad.

Is he married to the large platform concept? If minimal felt recoil is the top priority, it would seem that an AR15 would be the better bet.

 

[Trochlea]

He is pretty set in his desire for a large frame AR. Stubborn Vietnam veteran? Who ever heard of that? Anyway, I figured if he didn't like anything about the build, I could just get a jump start on a build of my own. My current plan is the 6.5 creedmoor kreiger 22 inch barrel hthat already had a blended fox river (vais type) brake and an adjustable gas block. I read a couple different things and i'm thoroughly regarding buffers, heavy vs light etc. I will say that over the past week or two, i have been trying to do my homework on this stuff and coming from a bolt guns and 22's, large frame AR's are a bit daunting.

 

[Lizardette]

Edit: This says most of the same stuff as an earlier post of mine, which I did not think got posted. Sorry if there's any confusion.

Fitting a rifle properly to the shooter can do a lot to mitigate felt recoil.

If an A2 stock isn't long enough, for example, you could get one of the three-way adjustable butt-plates and put int on either an A1 or A2 stock. That will give him the exact length of pull needed (since those that I know of are continuously adjustable), as well as drop at heel, and cant of the buttplate. The model from Sierra Precision is affordable, and doesn't look to be designed much differently from the Accuracy Speaks model that I'm using.

If even the A1 is too short, a collapsible model kind of goes without saying. I haven't used it, but it looks like Limbsaver makes one that's adjustable in .5" increments and integrates some kind of recoil reduction system. They also have a recoil pad that fits onto 'most' (whatever that means) collapsible stocks. The CAA Sniper Stock may look attractive, but my experience with it has been hit and miss. When locked in one position, it wobbles. The friction lock on the cheek piece works well, but the one on the butt pad (adjustable for drop) doesn't.

As for bullet weight, 160 grains is heavy for .26 caliber. The big advantage of going to a smaller bore diameter is getting a higher B.C. for the same weight bullet. A 160 grain .264" bullet is probably going to have a B.C. similar to a 190 grain .308" bullet. Ok, that's a wild guess, but you get the idea. If the recoil from that 160 grain bullet ends up being too much, you're not losing a lot by going down to ~150 grain. Just a thought.