[Polish Taipan]

Could you please decsribe it and what it does for accuracy?
Could you do it to these aftermarket PSL handguards?

 

[Polish Taipan]

Thanks Cephus, I'm just doing some dreaming on a concept PSL. Trying to think of every little thing that may make it more accurate like RSA FCG, cryo treatment, and some handload match ammo. Thoughts?

 

[Polish Taipan]

7.62x54 PSL (Romak III). A while back Coldsteel sent me pics of his Romak III blank and it sparked an idea thats laid a bit latent til last night. His blank doesn't have the rear of the reciever cut like a Romak III yet, you have to do it yourself and weld the little "moon" reinforcement on. I began to wonder if one could forego the cutting and such and just set the rear up to accept a normal AK buttstock. I emailed him about it and although he didn't see why it wouldn't work, he wasn't sure that it would either. So here I'll blow my secret plan and see what you guys think.
Imagine a PSL with this buttstock

This pistol grip

and the above handguards.
I was also toying with the idea of a Duracoat camo job but I think black would look great too.

 

[Polish Taipan]

Heres the Coldsteel blank I was refering to:

 

[sks_hunter]

when a bullet travels down a barrel, the barrel actually oscillates, or vibrates. the less contact with the barrel the better, to let it oscillate freely. This is why a remington BDL will shoot better than a marlin 30-30. The BDL barrel is free-floating (nothing at all touches it), and the handguard for the marlin is strapped to the barrel, not letting the natural harmonics take place. In the case of my Browning .300 mag, it has a BOSS, which is a tunable muzzle brake. You can move it in or out to find a harmonic "sweet spot" for any given load. too much info...

 

[scubadvr]

Ok, so when do I want to glass bed and when do I want to havea free floating barrel?

 

[Polish Taipan]

Thanks for the explanation SKS, I was begining to get the concept today. Most people on two forums seem to think it would be a waste to do on an AK type weapon. I've heard only one say it will still help, and Cephus' "Try it and see". I personally don't see it costing that much and and I don't think it can hurt, so why not? Even if I got a marginal inprovement, that could make a difference at 600 meters .

 

[sks_hunter]

It is my belief that glass bedding gives a solid area for the receiver to set on, and makes the vibrations more consistant from one shot to the next (as in, say, a remington bolt action). when bedded on wood, humidity, temperature, and even how you're holding it can make subtle differences in how the barrel oscillates. The glass bedding minimizes this. I have a friend who has a Browning A-Bolt Medallion 300 MAG just like mine, and was grouping just over 3" at 100 yards, and mine was a ragged hole. I noticed that he had one finger curled around the top of the barrel when he shot. I told him to try without touching the barrel, and it tightened to 1" and less. In one of my Remington BDLs, a 270, I was having a hard time to find a handload that would group under 2". I found that the forearm of the stock was touching the barrel. I removed the stock, dremeled it out a bit, and now it shoots around 3/4" at 100 yds with cheapo remington core-lokts. If you can float the barrel, great. I'd always want a floating barrel over anything else. It's not possible with an AK, due to the gas tube and handguard, however, the glass bedding could only help. Just my opinion. Let me know how it works out for you... maybe shoot a few groups before and after, and see if it did help. I'd love to know!

 

[Polish Taipan]

Thanks again SKS, I think its a worthy experiment. BTW what do you think of the build scheme? Think it will work? Would I be better off jusr buying a Saiga .308 (22")?

 

[hcpookie]

I don't like to put more contact on the barrel, It has to do with harmonices. Please don't ask me to explain those. lol . I just can't see more presure on the barrel I'd make it fit tighther at the rec. What are you going to do this on and is it going to be the 7.62x54 or the 7.62x39 maybe I'm missing something.

My understanding (I haven't read the entire thread yet) is that in the absence of a free-float barrel setup (the better solution), the bedding will not INCREASE accuracy, but will make the grouping more consistent because the pressure against the barrel that the handguard imparts is more precise and therefore more predicable. It kinda "locks" the handguard into the same spot.

Things like bipods, etc. can really hurt accuracy. When I start a Romak build, I'm going to seriously investigate how to put a bipod mount on the receiver, like the SVD's bipod mount. I hope to make it a bolt-on ordeal but it may require permanent alterations, based on pics I've seen.

The harmonics would make perfect sense if you watched the gun fire from one of those high-speed cameras, where it films so fast it looks like slow-motion. You'd see the thing whip all around and look like it was falling apart!

Think of it another way - if you are pushing on a real heavy object, like moving an engine in the garage, or something like that, you could lean on it and "rock" it along the floor, and your leaning pressure would make it walk along... that's how the movers got my 600-lb gun safe into the corner.

Well, the handguard imparts that same "pre-load" onto the barrel, and so every time the gun fires, and violently recoils, the pressure from the handguard is pushing the barrel around, causing the grouping to open up.

Cryo treatment helps in that it aligns the metal more tightly, so this whipping motion is more likely to return to "true". Comparison of swinging a tree branch around the size of your finger vs. a broom stick. Both whip, but one less than the other.


I am parroting all of this from from past reads of the "experts", so if anyone has more info, I'm all ears!

hth,
- Jerry

 

[hcpookie]

Heres the Coldsteel blank I was refering to:

THAT LOOKS SWEET! Going to have to get me one of these soon...

 

[sks_hunter]

Thanks again SKS, I think its a worthy experiment. BTW what do you think of the build scheme? Think it will work? Would I be better off jusr buying a Saiga .308 (22")?

NO WAY (saiga)
Stay with what you're on to. That will be SUPER SWEET!!!
It looks FANTASTIC!!!

Pookster...you absolutely got it.
The reason you see fluted barrels is that the flutes make them lighter, and actually substantially stiffer to help reduce the oscillation, thus making them inherently more accurate. Same with bull barrels like you see on target rifles, only NOT lighter, but definitely stiffer. The theory behind a B.O.S.S. (Ballistic Optimizing Shooting System), like you see on the Brownings and winchesters, is to lengthen or shorten the barrel, to have the bullet leave the muzzle when the barrel is at it's flat point, so there will be no side to side or up and down thrust on the bullet. Sounds hokey, but they work super well.