Help interpreting range data - 30-06 and 270

[bison]

New reloader here working on 270 and 30-06 hunting loads - I worked up a bunch of each and went to the range last weekend and am looking for tips on how to interpret what I found. The goal is to find a good hunting load for CA game (primarily blacktail and hogs).

Protocol for each was same - I loaded five shots of each of a number of powder loads from starting load to near max recommended, using the same COL for each. All loads were with H414, LR primers, and Hornady 165g Interlock (30-06) and Hornady 130g Interlock (270) bullets. COL for -06 was 3.23, for 270 was 3.13. Rifles are Win M70 (-06, new so I'm not really familiar with it yet) and Tikka T3 (270 - aways been a great shooter with factory ammo).

So off to the range....

For the 270 I loaded between 50 and 52.5g of powder in 0.5g increments. The lowest (50g) gave a great pattern of 0.4" and was dead on where I'd zeroed the gun at 100 yds for factory 130g Corelokts (2" high). Next best was up at 52.5g (0.75"), with intermediate patterns in the 1-2" area. The 52.5g loads shot about 1" higher than the 50g loads, so I assume that there wasn't a big difference in velocity.

Where do I go from here? My inclination would be to try +/- 0.25g around the 50 and 52.5g loads to see if there's any difference. I'm not sure about playing with COL as in order to get close to the lands I'd barely have the bullet in the brass.

The -06 was a bit more confusing. I loaded between 51 and 56g in 1g increments. No great patterns, best was 1.1" (55g) with the rest in the 1.5" range, so I'm less clear on what load to concentrate on. Of interest was that there was a couple inches of vertical difference between the 51 and 56g loads, so clearly a lot of difference in velocity. How do I think about this in the context of a hunting load? I'm unlikely to shoot further than 300 yds but I fear (?) that a lower velocity would lead to a lot more drop past 200 yds than a higher. I can also play with COL - using a smoked dummy I found that the max COL before hitting the lands was 3.245", so at 3.230" I'm 0.0.15" off. Would trying say 0.010" be the next step?

Incidentally I also loaded 5 of each caliber with magnum primers in the mid-load range and found no notable difference in the 270 and a wider pattern in the -06.

Thanks!

 

[243winxb]

the 270 The lowest (50g) gave a great pattern of 0.4" and was dead on where I'd zeroed the gun at 100 yds for factory 130g Corelokts

If you can repeat this, you have found your load for the 270.

The -06, best was 1.1" (55g)

If you can repeat this accuracy, your done. For hunting your accuracy is great. IMO.

 

[Ol` Joe]

Quote:
the 270 The lowest (50g) gave a great pattern of 0.4" and was dead on where I'd zeroed the gun at 100 yds for factory 130g Corelokts
If you can repeat this, you have found your load for the 270.
Quote:
The -06, best was 1.1" (55g)
If you can repeat this accuracy, your done. For hunting your accurace is great. IMO.

I agree.
The 270 load sounds like a real winner and the `06 is fine for hunting. There may be a change in accuracy for the better though in the 30-06 with a different wgt or brand bullet. I`ve very good luck with Hornady bullets in all my rifles but some have a slight perferance for any. Try a Nosler BT ot Sierra Pro-Hunter as example and see if accuracy improves. I`ve killed deer with all 3 bullets and they all behaved the same in my very limited experience.
There is likely no more then 200 or so FPS in your `06 loads from the lowest to top load, one no animal in the field will ever be able to tell. Change in POI is more the barrel changing its vibration pattern with variation in pressure then velocity. Sight in for your load, and don`t sweat it......

 

[JimKirk]

If you can get groups(shotguns are patterned) of .4" , you have an accurate hunting rifle, better than most. If I read it right you said you loaded 5 round, did you shoot in 5 shot groups or what? If you were getting 5 shot groups of .4" , you had better kiss that rifle on the lips and tell how much you love it! Now if you're saying that 2 shots grouped at .4" and the other 3 grouped at an "with intermediate patterns" in the 1-2" area, then you are still in the normal range, but you loads could still use some refinement. Please clarify the grouping and shot number per group.
The 30/06 is also within normal range group size, you may be able to shrink that some by refining the seating depth and bullet selection, that is the fun part of reloading, getting as close to the magic group size as possible.

Jimmy K

 

[ants]

I think you're doing great for a first try !!!

My humble suggestions:

When you're out of that H414, try IMR4350 next. Just a little slower burning. Many of us get good accuracy from IMR4350 (270 and '06) at slightly higher velocity. So it shoots the same, but flatter shooting at longer distance. (H4350 and A4350 are not the same as IMR4350, even though they are similar.) IMR4831 also works great in '06 if you go to heavier bullets.


'06 - Try 148/150 grain and 175/180 grain bullets. My M70 shoots 180 better than anything else. Yours may be different. [Definitely stick to 130g bullets in your 270.]


Cartridge OAL - Closer to the lands is NOT always better. The interior ballistics for long range competitive marksmen generally benefit from loading bullets at the rifling or very near, but those are rifles specially built for competition. Hunting rifles sometimes benefit, sometimes not.

Once you find the load that works best for your rifle, experiment with OAL long and short to fine tune the load; it may help or it may not. Also, find the right case length for your chamber, and stick with it. If you haven't gotten up to speed on 'shoulder bump' and case sizing, do a search. You don't want the cartridge rattling around inside the chamber when it discharges. You'll also get longer life on our brass. Also be sure to trim case neck consistently.

 

[bison]

Thanks everyone for the replies. JimKirk, I was referring to 5 shot groups. I will kiss the Tikka, though it's far uglier than the M70! Will try all the various suggestions, starting with different bullet weights. I'm having a good time reloading and see how this can turn out to be a serious hobby!

 

[kelbro]

One thing to keep in mind while working up loads. Your barrel begins to build up layers of copper and carbon fouling as you are shooting. This will have some effect on the loads. Often, your last few loads will work differently the next time you shoot if you shoot them first. I like to shoot mine round-robin style to spread the effect.

 

[ArchAngelCD]

Not much to add but I totally agree with the others on your .270. You are done searching for a load IMO. Your 30-06 isn't bad either but I have to agree you will probably get better results with 4350. I use 4350 with a 165gr Sierra GameKing and when I'm shooting well it produces sub MOA groups. (in a Howa Model 1500)

 

[JimKirk]

Bison
Beauty is only skin deep, but them M70s sure are pretty guns! You got a shooter with the 270!

Keep working with the 30/06, you may find a load it likes too.

Reloading is addicting, unless you make it into a job, then it becomes just like any other job. Keep it fun!


Jimmy K