Deep throats and tangent tips: a 22-250 FT love story

[blueridge]

I bought a Tikka 22-250 fast twist this spring and it has turned out to be the most accurate rifle I have ever owned. And it took some work to get there. My goal was a .5” - .75” gun to shoot steel out to 1000yds, have minimal recoil, and be relatively affordable in components to shoot. I backordered it on Eurooptic and had it in hand 2 weeks later.

I put it in a pillar bedded Boyds At-One, which I like a lot. One of the things I like most about it is the adjustable cheek piece. The front edge fits against the corner of my mouth like a kisser button on a bow, giving me consistent head placement. T3 & T3x’s come with a plastic composite trigger guard, which I replaced with real bottom metal from Mountain Tactical. Glass bedded the trigger guard, action, and scope mount. The barrel channel was a little tight so I inlet it a bit more to fully free float the barrel. After that, I was ready to start load development.

 

[blueridge]

To shoot the longer distances, I wanted a heavy for caliber bullet with high BC that would keep its momentum and cut through the wind. Since I would just be banging steel (not critters), that let me narrow down my choices quite a bit, and match bullets are much more available. 80gr is the upper end of what the 1:8 will stabilize, so I went with the 80gr ELD-M with the secant radius and boat tail. Oh, that secant radius. More on that later.

Went with H4350 as my powder and did the barrel break-in and initial pressure testing. Got up to 3300fps before pressure. I backed off a couple grains and loaded 4 in .3 increments from 35.5-36.7 for an OCW test. The scatter node at 36.7gr was easy to see (and from that have a good idea where the accuracy node would be: ~36.1), but damn all the groups were huge, around 2.5”+ at 100yds. Something was up. This was not the “inherently accurate rifle caliber” I had read and heard so much about.

Time to check some things and isolate some variables: torque settings on all the screws, primer change, putting it back in the factory stock, scope change. Nothing improved things.

Back to the bullet: bullets with the secant radius on the front (ELD, VLD, among others) give you that high BC that’s great for long range performance, but tend to be much more sensitive to seating depth and take more work “tuning” to find that magic recipe. Bullets with the tangent radius (SMKs for example) have a comparatively lower BC but aren’t as sensitive to seating depth and easier to please. Most of you may have known all that. I didn’t.

Time to measure the throat on this thing, do a seating depth test, and see if that improves things.

 

[WNC2500]

@blueridge i really like it. Sharp gun. Making me want to look for one of these 22-250's

 

[blueridge]

The loading manuals I looked at tested this grain bullet at 2.5” coal. There’s a custom ammo maker that makes a 22-250 & 80gr ELDM combo at 2.6”, so knowing that they would likely want to be closer to the lands anyway, that’s where I did my initial tests.

I knew from doing load development for my T3 in 7-08 that Tikkas (like Wetherby) are known to have a MILE of freebore. I even endearingly nicknamed my 7-08 “the deep throated high class hooker”. I know it’s a mid-class rifle, but I’m not rich. She’s high class to me. Anyway, back to the 22-250. I tapped a fired case, pulled out my comparator, and started playing a mix of mathematician and ENT. And hot holy hell! I could have the boat tail falling out and I would still not be anywhere close to the lands. So much for starting 20 thou off.



Starting with a OAL of 2.5” and using the end parameter of leaving the bullet’s diameter (in this instance, .224) of bearing surface in the neck case (disregarding the boat tail), doing a seating depth test in .010” increments was going to be a LOT of groups to shoot.

 

[pyrotechnic]

Back to the bullet: bullets with the tangent radius on the front (ELD, VLD, among others) give you that high BC that’s great for long range performance, but tend to be much more sensitive to seating depth and take more work “tuning” to find that magic recipe. Bullets with the secant radius (SMKs for example) have a comparatively lower BC but aren’t as sensitive to seating depth and easier to please. Most of you may have known all that. I didn’t.

Time to measure the throat on this thing, do a seating depth test, and see if that improves things.

You have secant and tangent confused.

What is the difference between a Secant, Tangent, and Hybrid Ogive?

A Tangent Ogive (like our standard BTs) is less sensitive to seating depth but has more drag and a lower BC than a Secant Ogive of the same length.

bergerbullets.com

 

[blueridge]

But it paid off, and the groups bore out just what was hoped for: predictable opening and closing with the barrel time, and overall group sizes getting consistently smaller and smaller.


Ended up with a great group (.291”) at OAL of 2.71”. After all that shooting, gave the gun a deserved good (but not too good) cleaning and loaded up 5 to see if it could be duplicated. Bottom left is the first fouling shot. Four shots together in the red.



But what would happen with a 77gr SMK? Would it be as sensitive to seating depth?

 

[blueridge]

You have secant and tangent confused.

What is the difference between a Secant, Tangent, and Hybrid Ogive?

A Tangent Ogive (like our standard BTs) is less sensitive to seating depth but has more drag and a lower BC than a Secant Ogive of the same length.

bergerbullets.com

You’re right. Told you it was new to me. Will edit. Thanks!

 

[pyrotechnic]

Thats good shooting! Glad you got it to tighten up. A fast twist .22-250 or .22 creed is definitely on my "want list".

ETA. What was the number of shots fired per group to make your plot?

 

[brockel]

I’ve got one tikka 8” twist 22-250 and one more showing up next week. Currently shooting 50 grain ballistic tips and 52 grain hornady hp for coyotes and has thermal sitting on it. It is an easy pleaser. The second one I’ll shoot heavies in as it will be my daytime calling rifle

 

[p_ham]

Being right up against the lands isn't as important as people make it out to be until you start trying to compete in BR or F.

 

[blueridge]

Ordered some 77gr SMKs and started over with both H4350 and Varget. Ends up that bullet manufacturers and their engineers actually know a thing or two. In both charge weight and seating depth tests with both powders, I couldn’t make it shoot over an inch. Granted, it was only 3 shot groups which don’t statistically mean sh1t, but it was encouraging for most to have 2 of the 3 touching. Ended up buying 500 when I shot this last one.

 

[blueridge]

Final thoughts and addendums:

In all reality, when expanding the number of shots, it’s probably a 1/2” gun with a 3/4” load with the SMKs. My 10 shot group with the ELDMs was right at an inch. How much of that increase is me, how much is the reloading variances, how much is the gun? Who knows? In the end, being an average shooter and relatively new reloader, and working hard to get sub-moa loads on my handful of rifles, these results are pretty satisfying.

Something I found EXTREMELY helpful: my buddy lent me his dedicated “load development scope” for the process. It’s a big, heavy, Bushnell (don’t see them getting too many mentions), 4-24x50 Tactical, FFP, very fine moa reticle, weighs a ton. I could zoom all the way in and be able to aim at the center of the 1/2” dot and still see an even amount of orange on all sides of the crosshair. Game changer compared to covering the whole dot due to reticle thickness or lack of zoom.

Another: I stopped using the lead sled a while back, but went back to it for these tests with two tweaks: no additional weight, and putting a smooth surface under it, in my case a board, so it can freely move backwards with recoil.

Had a friend tell me his takeaway was that the ELD-Ms and other high BC secant bullets aren’t worth the effort given the time and components it takes to work up a load, especially since tangents tend to shoot so good out of the gate. My response was the comparison of the ballistic charts. Even in the “little” 22-250, there’s a 300 yard difference when each these two loads go trans-sonic: 900 vs 1200 yards. In a hunting context, it’s irrelevant. In a long distance, steel-banging, just for fun see what my gun can do context, the difference is significant.

 

[blueridge]

What was the number of shots fired per group to make your plot?

Only three for the initial tests. Just enough to show me where to look closer.

 

[blueridge]

I’ve got one tikka 8” twist 22-250 and one more showing up next week. Currently shooting 50 grain ballistic tips and 52 grain hornady hp for coyotes and has thermal sitting on it. It is an easy pleaser. The second one I’ll shoot heavies in as it will be my daytime calling rifle

What’s the thermal you’re running? Been looking at the “cheap” ones.

 

[brockel]

What’s the thermal you’re running? Been looking at the “cheap” ones.

Bering optics super hogster. What are you looking at and what are your plans for it

 

[Flylo]

Hopefully we can keep this thread alive as brockel gets his new one up and shooting. I just got one of these tikkas as well and have plans to do many of the same upgrades. So far I’ve only been to the range with it once. After I burn through the last of my random mix of ammo leftovers from the last 250, I plan on dialing it in with 55 bt for the dogs and chucks. 70 Barnes or hammers for some heavier lifting on freezer filling tags,and undecided on some heavier long range steel bangers. I put a Leupold on plan on getting several different cds dials ordered for different loads. Ya I know I’ll be wearing out this barrel.

 

[brockel]

Hopefully we can keep this thread alive as brockel gets his new one up and shooting. I just got one of these tikkas as well and have plans to do many of the same upgrades. So far I’ve only been to the range with it once. After I burn through the last of my random mix of ammo leftovers from the last 250, I plan on dialing it in with 55 bt for the dogs and chucks. 70 Barnes or hammers for some heavier lifting on freezer filling tags,and undecided on some heavier long range steel bangers. I put a Leupold on plan on getting several different cds dials ordered for different loads. Ya I know I’ll be wearing out this barrel.

Already have one up and running since this last winter. My newest one will be a while. Having barrel cut off at 17” or 18” and threaded so it will be a little while

 

[BackofBeyond]

Already have one up and running since this last winter. My newest one will be a while. Having barrel cut off at 17” or 18” and threaded so it will be a little while
View attachment 229320

What’s the deal with the coban wrap?

 

[brockel]

What’s the deal with the coban wrap?

Keeps the cable I run from a battery pack in the cheek rest tucked away out of the way. Also holds the chunk of foam im using as a cheek rest

 

[Flatbrimmer]

What’s the deal with the coban wrap?

It gives it character. That gun’s name “Rocky”?