Flat Base or Boat Tail...

[drewsshootingsports]

Hello all,

I'm new here, and I'd like to say you have a very informative forum running! All of us less-experienced guys thank you!

I have just completed my first ever set of reloads, for .22-250. I was only able to shoot @ 100yds, but will soon head out to 300 and beyond. I loaded 50 rds, working load increments for 25 rds each of Berger 55gr FB and Hornady 52gr HPBT.

My question is this: How far out will I be going before I notice a "need" for the Boat Tails, if any? I do understand that these weight bullets won't really be doing me much beyond something like 400 or 500 yds anyhow, so is the point moot?

What I found @ 100yds was that the Bergers out-shot the Hornadys in my rifle hands down, but I still have the top half of the velocity range to test in the Hornadys and the bottom half in the Berger (even though I have already had very good groups w/Bergers, the trend was more accurate with less powder). I'm going to work the rest of the Hornady powder range just to be certain before I ditch them, but I am hoping to be able to extend these shots out as far as my equipment and skill can reach them, so I am wondering if I should (if the Hornadys don't work out) try some other BT ammo to help develop a good load that will maximize distance? (I'll probably be loading SMK next, any input on whether I should use 1400 or 1410?)

Also, if I am shooting 5 shot groups @ 100 yds (minimum 3400fps velocity) in zero to 5kt wind, and I experience horizontal strings in my groups, what's that all about? What are the odds that it's just me biffing it? (I had a few groups with less .14"-.25" vertical separation, but 1.1"-1.7" horizontal...)

I am shooting a Stevens 200 and that el-cheapo sythetic stock is a bit of a flexible flyer. Is it possible that it is getting "too close" to the barrel (laterally) and I'm getting a bit of inconsistent contact interference, inducing lateral group spread?

Input will be appreciated. Thanks in advance.

 

[fdshuster]

DSS: In my opinion, more important than flatbase vs boatail is the issue of your throat depth: How close to the lands can you seat the bullet and still have a reasonable amount of the bullets .224" diameter contacting the case neck? Bullet seating depth will have a lot of effect on your group sizes. I'm not familiar with the Stevens offerings of twist rates, but if it's the typical factory 1-14 you will be limited to bullets around 55 gr. max weight, and those (and lighter) bullets have a very short bearing surface when they include a boatail, the main reason I prefer the Sierra 53 gr. #1400 (flatbase) over the 52 gr. #1410 boatail. With some of these short, lightweight 22 bullets with a boatail, you are close to shooting a 22 cal. marble or round ball down the barrel with very little bearing surface. I don't hesitate to use flatbase bullets to & including 300 yds., but at greater distances, do prefer the boatails. They do have better downrange ballistics, but as yo said with a "little" bullet it may be a moot point anyway. Yes, I agree the Berger bullets are extremely accurate, my "standard" choice in 6ppc, 22BR, 6BR, etc. Horizontal spreads, for me, are usually a result to downrange winds, and unless you are using a good set of wind flags, you'll never know. Another problem is the forend on your Steven's, and the possibility that it's moving around a lot (left & right) when the rifle recoils. The reason benchrest rifle stocks have wide, 2 1/4" and 3" flat forends. The placement of the rear bag is also very important. During firing the rifle must recoil straight back without any kicking to either side. All these factors, (wind, bag placement, recoiling) will effect horizontal spreads.

 

[drewsshootingsports]

Fred: Thanks for the insight. The Stevens has a 1-12" barrel, and I am currently building a heavy walnut stock for the thing (I also plan to put heavier barrel on it in the future). I made dummy rounds for both bullets, and I believe I have a fairly accurate method to seat depth. According to my notes, I had the Bergers .05" off the lands, with effectively a full neck of seating surface. The Hornadys were .015" back from lands, but with less contact surface in the neck... You may be correct on this issue. I'll go back and check the seating depth. My rifle shoots factory Hornady V-Max rounds under .5 MOA, and they have those V-Maxes jammed quite a distance into the case... I think they "jump" quite a bit to the rifling, so maybe I'll tuck the Hornady Match BT a bit farther into the case.

It kind of makes me wish someone had a BT match bullet that was juuust a bit heavier... low 60s. The 1-12 might stabilize that, eh? I know this isn't a BR gun, but right now it's about maximizing my equipment's potential, and when hunting predator tournaments, I sometimes need to be able to pull the trigger on shots over 300yds.

Thanks for the help!

 

[camac]

Good advice from Frank.
It will be far more important at these ranges to go with accuracy. Pick your most accurate combination. A lot of shooters choose flat base 80 gr to shoot at 300 with 6BR's when the wind is down. The BC is a "LONG" way behind the 105-7 class but the increase in accuracy can make up for it if not too much wind. The (claimed) BC is actually in the Flat Based Bergers favour for these two anyway (G1 0.229 Hornady vs .267 for Berger) .

 

[DennisH]

I didn't completely read all the post!

But my VLP 22-250 with a 12 twist loves Bergers 52gr Flat Based Bullets, I have only shot up to 300yds, but have never shot in real windy conditions!

 

[deadlyswift]

Just a general rule of thumb, and being just from my own experience. Flat base bullets will stabilize quicker than BT's. AS well they seem to shoot more accurately at shorter ranges from 300 in. Boatails usely don't even settle down and stabilize until 300. That doesn't mean BT's want shoot really good at 100 or 200 yrds. Nor out shoot a FB. If it was me I would take Frank's advice and note how much bullet you have seated into the case. This will play more of a factor than any BT or FB bullet you shoot. If you can't get in the area of .224 of the bullet seated into the neck, I would maybe try some of the 60gr. bullets. Your 12 twist should be able to stabilize the 60's. Again being with my experience only, with berger's they like to be jammed, but every chamber is different. You may jump them a bit and get bad resluts but you could jump them even more changing the chamber pressure and entering one of the accuracy nodes of the barrel.

Good luck to you!
Nothing can replace trigger time!!

 

[357Mag]

Flat Base or Boat Tail...

DSS -
Howdy !

In your .22-250.... an external ballistics comparo of a 55gr FB to a 55gr BT would show that at a certain range ( distance ); the BT will start to edge-out the FB on flatness of trajectory.

Both notional bullets wouldn't necessarily start out w/ same vel even if propelled by same powder/charge and ignited by same primer. Differences in each bullet's
oal, bearing length, best seating depth will affect the case/powder space; and subsequent internal & external ballistics.

In my opinion, I don't think a BT " comes-on " for a .22-250, until ranges exceed
400+yd; and perhaps even closer to 450. IF you are going to shoot that far
( and farther ) w/ a .22-250 55gr, then you very well may want to wring-out every last bit of ballistic efficiency use of a BT can provide. If you predominately shoot under 400yd distance and esp if the FB group better for you; then use of a BT diminishes in it's percieved value.

I shot a slightly larger capcity .224" calibre wildcat , to get into the " 500yd club ".
The gun had a 24" 1-14 5-groove SS barrel. For the shot ( on a live groundhog )
I knew I was running marginal on kinetic energy. Certainly, I did not have a glut of excess power margin. For the shot I abandoned use of the 55gr SXSP that was used in my gold stanrd load for many years: and went w/ use of Hornady prototype
.224" cal 55grBT " V "-Max. I wanted to wring every last ft lb out of the load that
I could. I made the shot, but was left w/ the education that an improved load combo would serve me better.

I ended up going to use of the same wildcat in a 28" 1-8 5-groove SS barrel.
The resultant rifle offered 1,000yd clean-kill capability, but i had to go to use of Hornady 75gr "A"-Max " VLD in-order to get the ballistics/enegry figures that I needed.

My point:
Use a BT or VLD when you need to/have to; otherwise......

Best of luck in your endeavors.

Regards,
357Mag

 

[drewsshootingsports]

Well, guys, thanks for good advice. This forum is fantastic. Do you fellas know if anyone makes a low 60s grain BT match bullet? I'm going to give Berger's 62 (I think) FB a try, but I'd like a BT to try also. I now I'll have better options when I re-barrel to a 1-8", but I'm going to get some use out of this stocker first (it does shoot awfully well for a cheap gun... In fact, I'm pretty much to the point that when someone asks what rifle they should buy, the first word out of my mouth is "Savage").