5.45x39 vs 5.56x45?

[Shawski]

Corrosive ammo isn't bad, only takes me about 20 minutes to clean my AK74 shooting the cheap surplus 7N6 from Fleet Farm. And I wouldn't worry about the gas tube on a AR shooting corrosive, they're stainless steel.

[Collector1337420]

I'd stay away from corrosive ammo, but that's just me. If you don't mind cleaning your rifle for 2 hours after every time you shoot, then by all means, go for it.

With the Huldra piston style, is there as much cleaning?
Thanks

I would say it is less (as in easier) to clean than a regular (DI) gun, but the fouling is just in a different location, it's not actually less quantity. In a DI gun, the fouling is in the barrel and chamber, in a piston gun, the fouling is in the barrel and up by the piston (the piston itself, the gas ports, under the hand guard).

If you shoot cheap ammo, I recommend a piston upper, but the cost my outweigh the ammo savings. There are pros and cons to piston uppers, just like regular DI uppers. The DI vs. piston debate is like 9mm vs. .45 or AR vs. AK, there's a million articles and youtube videos. Do your research and figure out what's best for you.

[FJ540]

Piston vs DI is not like 9mm vs 45.

With a piston, you have reciprocating mass operating against your barrel before the bullet has left it. Seems silly to go to lengths to eliminate handguard interaction, and then put a slide hammer on the barrel.

[Collector1337420]

Piston vs DI is not like 9mm vs 45.

You don't think the debate between those two are similar to other debates over what's better?

[FJ540]

No, because rather than discussing the merits of a bullet which has performance changed by the weapon it's shot out of, you have a direct physical contradiction with DI and Piston AR's in the same operating configuration otherwise.

One has no moving parts on it's barrel, the other has several. Moving parts on a barrel which is also moving (dynamic interaction with the bullet traveling through it) is a recipe for inconsistency, especially when you consider as there's more fowling in the piston, it will behave differently.

I'm not saying one will work and the other won't - I'm saying you have a distinct physical difference on the piston configuration which will change accuracy in a negative way. What you gain with that loss is less crap being blown into the receiver, but your shot consistency will suffer for it.

It might not mean the difference between a 2 and 1.5 MOA gun - but if you were going for sub-MOA, I'm gonna bet you'll have trouble getting there with a piston which isn't disabled. Les Baer won't guarantee less than 1MOA on their piston guns, and their DI ones are 1/2.

[Dave Timm]

We list accuracy on ALL of our guns as 1 Moa at 100 yards or sub that on our match guns with good ammo. Now obviously Russian surplus isn't the most accurate but I have proven our 545 guns are capable of that using new production Hornady. And yes, all of our Huldras are piston and they are accurate. A recent article in GWLE also showed that as the author had a 1" group at 100 yards and his other test ammo were all around 1.25". I think it was feb issue and that was with our 14.5" gun.

I regularly shoot carbine classes with both DI and piston and I would say the piston parts after 2000 plus rounds are easier to clean then the carrier of a DI gun. I'm really not biased as we have both rifle types and there really are pros and cons to both. I own both and like and dislike things about both operating systems. I can honestly say that accuracy isn't an issue.

Dave

[FJ540]

So you're falling in line with Les Baer, who won't guarantee anything better than 1 MOA on a piston either.

[Dave Timm]

I see what you're saying, and on our Xpre we list that as sub MOA. We list our accuracy on all of our guns not just custom stuff like Les does, for example his ARs average at what $2000+. I'd be shocked if you had an Xpre, with match ammo that didn't shoot half Moa at 100. We have customers send us feedback constantly and quite a few get sub Moa even with 55gr bulk ball. If the shooter and ammo is up to it, our base model will do 1 Moa at 100. The point I was making is there are not very many, if any anymore, companies that list accuracy for production M4 battle rifle type $1050 guns.

I used to really believe the piston are less accurate thing, but seeing my Xpre, 16" and 18", shoot at 600 yards I don't anymore. There were times I really sucked at reading the wind, but when it was on it was on. I totally get the harmonics, piston movement etc in fact I've studied it under high speed camera looking for barrel whip and flex and studying the cycle. I'm just not that convinced anymore that a quality piston has to be less accurate because of the piston. We sell both DI and piston so I'm really not biased but I see much more accuracy issues stem from the chamber, throat, crown, ammo, heck even installation of the muzzle device as barriers of accuracy then the operating system. Now I don't know what piston system other manufacturers use and to be honest didn't know Les had a piston gun at all. Both systems truly do have their pros and cons.

We sell a precision DI rifle that's a heck of a shooter as well, but my 18" piston gun will shoot just as well as my 18" Noveske SPR build. If someone wanted a precision rig I totally understand the logic of using DI, but there are some sweet shooting piston rigs out there too, not just in the AR platform.

Not trying to stir an argument and on paper I still get the argument between the two.
Good discussion.
Dave

[FJ540]

No argument at all. I have $850 in my poodle shooter (18" White Oak barrel) and based on the short range performance I'm pretty sure that one's going to be 1/2MOA or better. I don't agree with what the custom shops charge when they don't add any value. I'm pretty sure an outfit like Adams would be able to assemble a gun just like mine for the same price and have the same results.

It's not about throwing gobs of money at the problem, it's about putting the right dollars where they belong and not worrying about the rest.

[Dave Timm]

Sounds good, white oak makes some very nice barrels. I look forward to seeing you post with some updates. I love anything ar so it's always cool to see builds and what people like.
Dave

[kollector03]

I picked up a 5.45 Huldra upper because I really like the 5.45 round and the Huldra piston upper looked to be a really good value.

Mine runs fine on a standard Spikes lower. I did install the extra power hammer spring. I also have a S&W 5.45 upper that's a DI design and I definitely like the Huldra better.

I use ASC 5.45 mags as well as PMAG-30 M2 mags downloaded to 22 rds.

I liked the Huldra upper so much I did find and purchase one in 5.56 as well.

Don

[grousemaster]

Sounds good, white oak makes some very nice barrels. I look forward to seeing you post with some updates. I love anything ar so it's always cool to see builds and what people like.
Dave

My experience with piston vs. DI is that pistons are more sensitive with ammo. Under powered ammo works fine in my Korstog/PSA uppers. However, use Wolf in a Huldra....and get back to me on performance

Not saying Wolf os the measure of a quality gun, but it's nice to know that a rifle will eat up about anything if needed.

[Dave Timm]

I see what you are saying, and I will agree but also say that a couple points. We purposely don't over gas our piston guns, in fact the gas port is generally the same as our DI size. Obviously it takes more energy to cycle a piston then for gas to travel down a tube. Sometimes the reduced power spring as a tuning piece will take care of lower powered ammo and that's the end of it. If a customers wants us to open the gas port so it runs with steel brand X we can do that. It's a fine line from proper gas to over gas and we would rather err on the side of not over gassing. Some brands purposely over gas and when you look at their gas ports they are huge. They do this so guns will run with lower power ammo and not deal with complaints, however the risk is premature wear, breakage etc. Now most people never shoot more then a few thousands rounds in the life if the rifle so these companies don't have to deal with it. We like to build our rifles for the guys who shoot a few thousand rounds at a class a few times a year and the rifle lasts with no concerns of broken bolts etc.

[grousemaster]

I see what you are saying, and I will agree but also say that a couple points. We purposely don't over gas our piston guns, in fact the gas port is generally the same as our DI size. Obviously it takes more energy to cycle a piston then for gas to travel down a tube. Sometimes the reduced power spring as a tuning piece will take care of lower powered ammo and that's the end of it. If a customers wants us to open the gas port so it runs with steel brand X we can do that. It's a fine line from proper gas to over gas and we would rather err on the side of not over gassing. Some brands purposely over gas and when you look at their gas ports they are huge. They do this so guns will run with lower power ammo and not deal with complaints, however the risk is premature wear, breakage etc. Now most people never shoot more then a few thousands rounds in the life if the rifle so these companies don't have to deal with it. We like to build our rifles for the guys who shoot a few thousand rounds at a class a few times a year and the rifle lasts with no concerns of broken bolts etc.

I agree with your added points. I also notice carbine length systems cycle under powered ammo better than rifle length systems....

[cigartim]

I have 2 5.45 ARs and love them. Ammo is cheap, especially since I stocked up on 10k rounds when it was going for $130 per 1080 rd. can. I liked my first one, which was built as a cheap beater rifle, so much I built a 8.25" that is awaiting a tax stamp. Pmags work if you download them, but not as well as dedicated 5.45 mags. the problem is that the lower case neck causes rounds to nose down and jam against the front of the mags. In 30 round pmags I didn't have problems when loading 10, but had occasional problems when loading up to 25. Bad news loading more than that. I advise to only use pmags in a pinch and stock up on 5.45 mags when you can.

Here is the shorty. I just posted this in the gun pic thread.