52gr bullets too light for AR with 1in7" barrel?

[Detritus]

Getting ready to start reloading for my Wife's AR, which happens to have a 1in7 twist barrel.
I thought I had a box or two of 55gr or a partial box of 69gr smks in the stash...

But the heaviest .224 pills i have are some Sierra 52gr ones that i can't remember offhand if they're the flat base "varminter" profile or the boattailed "matchkings".

I have fired exactly 35 rounds of ammo through this barrel that were not surplus 62gr "M855 equivalent", those 35 were all 52gr hps of the same type as found in the bullet stash, and made a shotgun like pattern on a USPSA target at 100 yards. BUT! those were all 20+ year old handloads for a long traded away savage.
so i can't be sure if it was a case of too light a bullet or just not an appropriate load overall for the gun.

so what say you, is it worth trying the 52s in a 1in7 barrel or do I HAVE to look for some 55s or 60s minimum?

 

[troy fairweather]

Think you should be fine, I'm shooting 40s in my 1-8.

 

[ms6852]

I have 1/8 on AR's and don't like the light bullets. You will never know how it shoots those until you try it. If it works great if it doesn't now you have an answer to your wife's AR limitations.

 

[Detritus]

Think you should be fine, I'm shooting 40s in my 1-8.

that's encouraging.
Also I'm pretty sure i'll be ok if i work up a decent load, i'm just covering my bases.

I'm just trying to get to where I have more than one decent range trip worth of ammo for the AR, so I'm saving the 40s I've got for when I start piddling with 22-Hornet again (it's what they were bought for 20+ years ago).

 

[Blue68f100]

Depends on which chamber you have in your gun. A chamber with long leads may be a problem with the light/short pills. The only AR I had with a 1:8 (Wydle) twist did not like anything under 60gr.

 

[SlowFuse]

I agree with what some have said, depends on the gun.

I have a 1:7 that shoots 53 grain Hornady VMax lights out, but wont group a 50 grain "dogtown" soft point. The differences here (besides the 3 grains which to me is pretty negligible) is the flat vs boat tail base and a soft tip vs ballistic tip... one of those variables in construction and maybe the weight is making a difference.

Unless you already have a good stash of the light bullets I would go heavier for the 1:7. 60 to 69 is my favorite range for general under 3-400 yard shooting with 223. If you want something match style Midway has Sierra TMK 60 grain for an ok price.

https://www.midwayusa.com/product/1020151176

 

[jmorris]

It’s not weight, rather construction. The Speer 52 gn JHP’s I have will come apart from centrifugal force in a 1:7, they can’t handle the RPM a twist that fast gives them moving at .223 velocity’s. Bullets that are less fragile still shoot just fine.

 

[AJC1]

It’s not weight, rather construction. The Speer 52 gn JHP’s I have will come apart from centrifugal force in a 1:7, they can’t handle the RPM a twist that fast gives them moving at .223 velocity’s. Bullets that are less fragile still shoot just fine.

This was one of two important things. If you drive them hard they can come appart. Rpm above 300,000 seems to destroy bullets. The second is at higher rpm any imbalance will be magnified. 1:7 is the highest stable twist rate in 223 and usually the best performance is with heavy bullets. The 77smk and 75 hornaday were designed for mag length loading in ar rifles. The 69 also works well for most. Happy blasting

 

[TonyAngel]

As a general rule, 52gr is fine in a 1:7. Athlete will be exceptions though. Fragile bullets won’t like it and each barrel has its tastes.

 

[Demi-human]

I have a seven twist barrel that is fine with 50 grain Vmax bullets but Poofs 50 grain SPSXs.

With light loads it will keep the SPSX intact. Increasing the charge will cause a reliable bullet failure at shorter and shorter distances.

Through one side of a card board box into shards by the other side.

The Ultimate Varmint Load, it self detonates even with a miss! Perfect for suburban areas! (as long a the neighbors don’t mind the deafening blast of 2x.xx grains of CFE223...)

 

[rskent]

so what say you, is it worth trying the 52s in a 1in7 barrel or do I HAVE to look for some 55s or 60s minimum?

If you want to shoot some great 100yd groups out of your AR you might try a Sierra 52 HPBT over 23.5 grains of 335. It sounds light and it is. But it shoots great out of several 1 in 7 twist barrels I have tried it in.
If it doesn’t, just switch the boat tail with their 53-grain flat base.