55 gr fmbt or 62 gr fmjbt for general practice

[NRAShooter]

For the 223 in an 14.5-16 inch AR M4 type 1x7 twist platform, what are your thoughts on the optimum fmj bt bullet weight for practice ammo? Both 55 and 62 gr fmjbt are available in quantity at reasonable prices. No, these are not Sierra Matchkings and I wouldn't buy them as such.

Looking at using this for cqb, unorthodox position, barricade and general shooting out to 400 yards at IPSC size targets and the like size steel plates.

If I need match ammo for precision work or longer ranges will use Mk262 clone in Mark 12 Model 0.

Any suggestion and your thoughts on why would be appreciated. Any load recipes would be an added bonus.

Thank you in advance.

 

[CK_32]

Re: 55 gr fmbt or 62 gr fmjbt for general practice

Im looking for the same answer. I have a 16" 1:7 I've hear rumors of 55g bullets blowing up after leaving the barrel due to the fast twist rate.

 

[Super Bee 950]

Re: 55 gr fmbt or 62 gr fmjbt for general practice

The 62 fr SS109 bullets from Wideners shoot great out of my 1/7 AR.
http://www.wideners.com/itemview.cfm?dir=278|281|727
The 62gr FMC that Wideners sells are good blasting ammo, but the group size is double the SS109.

Hornady 55FMC are the best 55gr round.

 

[jbailey]

Re: 55 gr fmbt or 62 gr fmjbt for general practice

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CK_32</div><div class="ubbcode-body">Im looking for the same answer. I have a 16" 1:7 I've hear rumors of 55g bullets blowing up after leaving the barrel due to the fast twist rate. </div></div>

No way. 7twist will shot a 30gr bullet fine (hell of a lot of spin drift, but they will not explode).

I would personally use the 62gr - they will shift less from barrel heat.

 

[samnev]

Re: 55 gr fmbt or 62 gr fmjbt for general practice

62 grain is what I use in a 1:7 twist. 55 in 1:9 or 1:12 twist

 

[1Sg (ret)]

Re: 55 gr fmbt or 62 gr fmjbt for general practice

Try 55 hornady fmj.24.5gr h335.Rem brass cci 41 primer @ factory length.They shoot great out of all rifle i have tryed them in.Hornady projo being the key.