Is this weird? 20" rock better with 155 than 175

[robdes]

So, at the range today I was shooting at 200yrds. I was shooting FGMM 168, and 2 flavors of the southwest ammo- 175 smk's and 155 scenars. Its a newish rock creek barrel that is 19.5". I seemed to be getting the best results with the 155gr bullets (a touch over .75" groups) I am not too consistent a shot, and I did seem to feel a bit more on top of it while shooting the 155's- they were my last shots of the day.

Has anybody else had this experience, that is their rock barrel liking the 155's? Should I buy a sh*t ton of that ammo, or do some more testing?

 

[81sfo]

Re: Is this weird? 20" rock better with 155 than 175

Every barrel is diffrent ,some shoot the 155s good some dont.If your barrel shoots the 155s best then get that particular ammo/bullet for it.I handload,for short range 600 and under i use the 168 smks becuase they are cheaper than the 155 scenars.For shooting at Bayou 1000 yd F/TR match i use the 155s.Use what your rifle likes best.What distances do you usually shoot out to?

 

[robdes]

Re: Is this weird? 20" rock better with 155 than 175

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Forwardeyes</div><div class="ubbcode-body">Every barrel is diffrent ,some shoot the 155s good some dont.If your barrel shoots the 155s best then get that particular ammo/bullet for it.I handload,for short range 600 and under i use the 168 smks becuase they are cheaper than the 155 scenars.For shooting at Bayou 1000 yd F/TR match i use the 155s.Use what your rifle likes best.What distances do you usually shoot out to?</div></div>

I haven't joined bayou yet, so I usually shoot at ASC at the 2 and 300 yrd ranges. I do some shooting at 400 and 500 yrds at friend's ranches. I will probably join Bayou this year (I am actually looking at the 2011 dues stmt on my desk) so that I can stretch it out a bit.

That's good to hear that you are using the lighter bullets out to 1k.

Thanks

 

[81sfo]

Re: Is this weird? 20" rock better with 155 than 175

I shoot at Asc every weekend unless rain stops us.were over at the 600 yd line. I'm not a member at Bayou,I just attend the 300,600,1000 yd matches.$20 for non members.let me know next time you'll be at Asc.

 

[robdes]

Re: Is this weird? 20" rock better with 155 than 175

Cool, will do.

I'll try to make it out next weekend.
Thx

 

[Gewehrsmann]

Re: Is this weird? 20" rock better with 155 than 175

It has everything to do with the rate of twist in the barrel. Fast twist for heavy bullets, slow twist for smaller bullets... In the 30 cal, a rate of twist in the 1 in 13 would stabilize the 155 grain Palma well... 1 in 10 should do well for the 175 grain SMK

 

[robdes]

Re: Is this weird? 20" rock better with 155 than 175

MIne is a 1 in 11.something (I think .25-not sure)

 

[deadly0311]

Re: Is this weird? 20" rock better with 155 than 175

While the weight plays a good part in the twist rate, the bearing surface has more to do with the twist....

For example my 223 wont shoot 75 AMAXs for shit, but it will shoot the 77 SMKs like a house on fire. Its a 9 twist. Weight isnt the biggest factor but the overall bearing surface of the ogive.

 

[vman]

Re: Is this weird? 20" rock better with 155 than 175

dtac you will find as your barrel has more rounds down it, you become more consistent with your shooting and you tailor a round to your rifle... almost any .30cal projectile will shoot good.

It could be that your shooting was better towards the end, as this is common with new shooters.

Or it could be that your barrel likes that SW Ammo 155 scenar recipe.

 

[six 4 sure]

Re: Is this weird? 20" rock better with 155 than 175

My FN SPR likes the 155's signficatly better than anything else I've tried.

 

[5RWill]

Re: Is this weird? 20" rock better with 155 than 175

I shot a group of 168s out of my 5R, pretty good. Then i shot a group of 155s that blew it away. Twist is 11.25

 

[Willys46]

Re: Is this weird? 20" rock better with 155 than 175

Just my $.02, if you planning on going out further, say 800+ you will be better served with the 175's. In my 20" the 155's shot great to 850 and the wheels fell off. To get the best performance you need to push the 155's to 2950. I found the 175's to shoot WAY better at 900+.

It seems the 175 just does better through transonic..the 155 are great if you can get them going faster, but in 19.5", that will be tough. It can be done, just not as easy.