OCW test results

[Hinter686]

Hi guys, I just shot this OCW test for my Tikka .204 and was looking for a back up opinion. When i was in the field i chose one of the loads i deemed best and loaded 3 rounds up with a .4 grain spread and shot a 1.85 group at 300yrds.

I'm not going to state what charge i chose, but would like to ask what you think in case i have missed something of potential.

Thanks for all your input.

Hunter686

[Rick in Oregon]

If you want your target pics to appear, use the "IMG" code, not the 'http' code.

I'm sure someone will chime in to help you if they could just see the targets on the forum.

[Hinter686]

Cheers Rick, all sorted (Y)

[skipper]

What powder were you using? You seem to have a couple of nodes worth examining further. Depending on the maximum safe load of the powder you might want to investigate the node around 25.0 a little more. If you can safely go above 25.2 you might have found an interesting load with better velocity.

These type tests are difficult to read depending on many variables. The results are subject to shooter ability, changing conditions, etc. Just be safe. If you are shooting a 1.8" group at three hundred yards, I would be happy with that.

[Hinter686]

What powder were you using? You seem to have a couple of nodes worth examining further. Depending on the maximum safe load of the powder you might want to investigate the node around 25.0 a little more. If you can safely go above 25.2 you might have found an interesting load with better velocity.

These type tests are difficult to read depending on many variables. The results are subject to shooter ability, changing conditions, etc. Just be safe. If you are shooting a 1.8" group at three hundred yards, I would be happy with that.

Thanks for the input Skipper the powder I'm using is 10x. The suggested max load is 25.1 so i went over max for the last charge but didn't have any pressure signs at all.

The charge I chose was 24.0. Slightly on the lower end of the range than i wanted. I am considering maby re-shooting 25.0 and maby pushing up to 25.4 or 25.6 to see if i can hit another node. The varmint only has a 20 inch barrel so i wouldn't mind making up the velocity provided i can do it safely.

[Bill K]

Looks like you should work around that 25.0 grain load, but near max, you may want to watch the temp change later in the summer for pressure signs. Safe and sane. Also watch the seating depth of your bullets. Bill K

[Hinter686]

Looks like you should work around that 25.0 grain load, but near max, you may want to watch the temp change later in the summer for pressure signs. Safe and sane. Also watch the seating depth of your bullets. Bill K

I live in Scotland so the summer temps don't tend to higher than about 28°C so I'm not massively worried, but i am aware that the 10x is temp sensitive.

As for seating depth, i can barley touch the lands as the tikka has a mighty deep throat so pressure spikes due to head space shouldn't be an issue as such.

I ran some targets today with +.030 and -.030 (2.230 & 2.290 OCL) and the groups were pretty rank. So, I'm going to work around the 2.260 OCL and see how it goes. The OCW targets were shot with 2.260 OCL.

You know what us reloaders are like, if it ain't broke? Try and fix it anyway

[Bill K]

Looks like you should work around that 25.0 grain load, but near max, you may want to watch the temp change later in the summer for pressure signs. Safe and sane. Also watch the seating depth of your bullets. Bill K

I live in Scotland so the summer temps don't tend to higher than about 28°C so I'm not massively worried, but i am aware that the 10x is temp sensitive.

As for seating depth, i can barley touch the lands as the tikka has a mighty deep throat so pressure spikes due to head space shouldn't be an issue as such.

I ran some targets today with +.030 and -.030 (2.230 & 2.290 OCL) and the groups were pretty rank. So, I'm going to work around the 2.260 OCL and see how it goes. The OCW targets were shot with 2.260 OCL.

You know what us reloaders are like, if it ain't broke? Try and fix it anyway

Yes, know all too well how "Us" reloaders are Just had a friend come back from Scotland, went to a wedding of a school chum. Enjoyed the trip and all. Closest I came to that area was UK and Ireland, years ago. Bill K

[skipper]

FWIW 25.1 grains of RE-10X is one of those "optimal" .204 charges with the 35 grain Berger and the 39 grain Sierra BK. It just seems to work well with so many rifles. CCI BR-4 primers should torch things off just right. Both of my rifles like them a LOT! Just beware of that nasty powder residue ring that builds up at the front of many chambers. A definite accuracy killer, for sure.

[Hinter686]

FWIW 25.1 grains of RE-10X is one of those "optimal" .204 charges with the 35 grain Berger and the 39 grain Sierra BK. It just seems to work well with so many rifles. CCI BR-4 primers should torch things off just right. Both of my rifles like them a LOT! Just beware of that nasty powder residue ring that builds up at the front of many chambers. A definite accuracy killer, for sure.

Interesting, its actually the 39 sbks I'm running. although Rem 7.5.BR primers. You can't argue that 25.0 is a nice cluster, although i know its not all about the size of the group.
Il re-shoot a another mini test with 24.9, 25.1 and 25.3. In dans N's instructions he tells you to go "1%" either side when loading the final 3 shots. Would you recommend just .1 either side or stick with the 1%?

The reason why I asked for a second opinion is that although really happy with the final group i shot (.6 MOA at 300 yrds) my gripe was is that came in at 5.5 inches low. That's 3.6 inches drop at 200 . If i wanted trajectory like that..... id have bought a 223

[skipper]

Since the 25.1 node with RE-10X is such a common sweet spot I would go with a ladder test with 24.9, 25.0, 25.1, 25.2, 25.3. This time keep it to 100 yards only and shoot five shot groups. Try to find where the group really tightens up. Now, this is going to have to be under as controlled conditions as you can manage. One little puff of wind could rob you of finding what you are looking for. Five shots will help rule out a bad trigger pull. See if you can beg, borrow or steal a chronograph and wind meter so you can really narrow down variations and extreme spreads. Then once you find that sweet spot go back to the reloading bench and start playing with seating depth. Load all the information into Point Blank and see if the trajectory suits you.

[Hinter686]

Since the 25.1 node with RE-10X is such a common sweet spot I would go with a ladder test with 24.9, 25.0, 25.1, 25.2, 25.3. This time keep it to 100 yards only and shoot five shot groups. Try to find where the group really tightens up. Now, this is going to have to be under as controlled conditions as you can manage. One little puff of wind could rob you of finding what you are looking for. Five shots will help rule out a bad trigger pull. See if you can beg, borrow or steal a chronograph and wind meter so you can really narrow down variations and extreme spreads. Then once you find that sweet spot go back to the reloading bench and start playing with seating depth. Load all the information into Point Blank and see if the trajectory suits you.

I like it! I have loaded up the above already to go and try when I'm next out. The weather has been excellent here ATM as far wind goes haven't had any bother with it. As for the chrono and the wind meter, I'm going to struggle I think! I would have just bought them but I just bought 2 tubs of 10x and some blitz kings so that set me back £110 ($164) not ideal I know but it's the best I can do ATM. A crony is on the shopping list for sure as well as a Kestrel. Il pick a day that day that's the best for the conditions and go from there.

[Hinter686]

Ok, update on the OCW test.

I loaded the above into 6 groups of 5 rounds and went to work. The groups were not as tight as the original with almost every group with a flyer. The conditions were decent with a very slight breeze from the tail. Although, I wasn't happy with the stability of the bipod as it would consistently move and I would have to correct it (Shooting on bare ground, mud/grass) but all groups were shot from the same constant inconsistency so although they weren't great none broke 1 MOA. After reading the Tea leaves (so to speak) I decided on 25.1 as it was also a promising group in the above test.
The final test I did was the same as above, 3 shots at 100 with a .1 grain spread either side. The group came in bang on MOA 2.8 inches (280 yards) but here is my issues the group came in 7 inches low at this distance. A bigger drop than the 24 grain charge unfortunately I don't have use of a crono so I can't check actual velocity.
I understand about barrel harmonics but don't understand how an extra 1.1 grains equals a lower poi at 300 yards

Can anyone explain this?

Cheers

Hunter686