.243 and H414

[roeboy]

Hello

 

To cut a long story short I have switched to H414 for the 243 shooting 87 grain vmax. Using hogdon data and some info on 6mmbr I've been working up a load near to max to get the velocity without the pressure I was getting by trying to achieve 3200 fps ish with N140. So far so good. No pressure signs with 44.0 and 44.5 grains. Some very light shiny marks with 45.0 grains so won't be pursuing that. The odd thing is 44.5 grains gets me a group of .319 inches but half a grain either side is utterly hopeless giving an inch at best!

 

I know charge weights can radically alter accuracy but is it normal for only 0.5 grains to show such a difference? I'm close to the lands at 5 though so does anyone who uses H414 who has more experience know if this is to be expected? In my experience with N140, changes in group size seem less extreme. I will stick with the 44.5 grain load at 3250 fps but I would be really interested to hear other people's thoughts! Thanks in advance!

[jcampbellsmith]

Hmmm, I'm no expert in these things, but I typically validate a charge weight by trying 0.2 gr either side of what's emerged as a likely weight. When searching for a weight with a new powder/bullet combination, I will typically move up in steps of 0.4 gr. I'm loading for a 243 AI and a 260 Rem.

 

Regards

 

JCS

[kent]

All I might say is I get great results with Varget in the .243 win using the Hornady Varmint 87 grain HPBT #2442. I had a hard job sorting the best powder fill on accuracy and had to get out a fair way to find it. 38.6 gave just under 3200 fps from a 20" barrel and ended up my choice, I got up to 3350 fps at 41.2 grains. This high end proved safe initially but I started to get pressure sign past 40 grains just occasionally, one stiff bolt lift ended my thoughts of squeezing more at 40.5. Norma brass,CC1 BR2. Not used H414 but like I say varget proved quite flexible as regards were the accuracy was between 38-40 mostly all produced 0.75 MOA at 200 yds but the bullets are not the favoured offering in my tube that produces better with other bullets ended up on 38.6

[The_Dogge]

42.4gn H414 under an 87gn V-Max was my standard load, and I may yet go back to it, it was good. Your +-0.5gn observation is normal, if you read the theory on optimum barrel time the difference between a scatter node (big group) and an accuracy node should be about 1% of the load, i.e. 0.5 gn on a 50gn load, which I have found often works out. I think 0.5gn steps are too big.

 

I got 3150ft/s from that BTW, I could not match that speed with Varget.

 

One more P.S., running loads like that in a 243 has its costs, according to the spreadsheet calculator on accrateshooter.com (google barrellifeupdate.xls) the barrel will be shot out in about 1400 shots. People don't seem to talk about 243 as a barrel burner, but it actually suffers from a pretty short barrel life. It costs more per shot than the bullets! Using a single base Viht powder would extend the barrel life considerably.

[kent]

42.4gn H414 under an 87gn V-Max was my standard load, and I may yet go back to it, it was good. Your +-0.5gn observation is normal, if you read the theory on optimum barrel time the difference between a scatter node (big group) and an accuracy node should be about 1% of the load, i.e. 0.5 gn on a 50gn load, which I have found often works out. I think 0.5gn steps are too big.

 

I got 3150ft/s from that BTW, I could not match that speed with Varget.

 

One more P.S., running loads like that in a 243 has its costs, according to the spreadsheet calculator on accrateshooter.com (google barrellifeupdate.xls) the barrel will be shot out in about 1400 shots. People don't seem to talk about 243 as a barrel burner, but it actually suffers from a pretty short barrel life. It costs more per shot than the bullets! Using a single base Viht powder would extend the barrel life considerably.

Really? I thought its short round count was very common knowledge among shooters and the main reason why its not much more used competitively. It will of course with the right twist and bullet choice shoot inside most things and has light recoil

[Will0]

I've recently moved to 87 gran v max with n160. I've found the same, the accuracy node seems a lot finer than my 80grain bergers.

Getting 3250fps from 42.7 of N160, 25 thou off the lands. Next job is to refine the load between 42.2 and 43.2 at longer ranges I think

[kent]

I've recently moved to 87 gran v max with n160. I've found the same, the accuracy node seems a lot finer than my 80grain bergers.

Getting 3250fps from 42.7 of N160, 25 thou off the lands. Next job is to refine the load between 42.2 and 43.2 at longer ranges I think

That's interesting that you feel the bullet is giving you that fine node, I found the revese with a its brother the #2442 87 grain varmint. I must say I personally really struggle to get meaningful results with most loads till the distance increases

[colin jalland]

That's interesting that you feel the bullet is giving you that fine node, I found the revese with a its brother the #2442 87 grain varmint. I must say I personally really struggle to get meaningful results with most loads till the distance increases

I use 40gr of H414 behind a 100gr sierra with real good results .

[Will0]

That's interesting that you feel the bullet is giving you that fine node, I found the revese with a its brother the #2442 87 grain varmint. I must say I personally really struggle to get meaningful results with most loads till the distance increases

Just my basic and broad test at 100yds. Lets me know roughly what's going on throughout the spectrum.

 

May I ask how much yours had to jump?

 

I've only got a 0.6" group so far with the 87s, isn't as satisfying as those bergers

[roeboy]

Thanks for all the replies! Dead interesting. I think smaller increments are the way to go. To be honest I'm pretty chuffed with the load at 44.5 grains as I shake like a shitting dog when shooting groups. Interesting about barrel life. Why can't life be simple. It's only used for foxing and the odd crow but I am really enjoying shooting groups further and further. This is a shame as I will be worried about barrel life now! Then again part of me thinks what the hell. What would you folks do? Would you worry about barrel life?

[jcampbellsmith]

Thanks for all the replies! Dead interesting. I think smaller increments are the way to go. To be honest I'm pretty chuffed with the load at 44.5 grains as I shake like a shitting dog when shooting groups. Interesting about barrel life. Why can't life be simple. It's only used for foxing and the odd crow but I am really enjoying shooting groups further and further. This is a shame as I will be worried about barrel life now! Then again part of me thinks what the hell. What would you folks do? Would you worry about barrel life?

If you're worrying about barrel life, it's time to find another pursuit. Barrels are just another consumable in my opinion. With the 243 you'll have an opportunity to get a 1:8 twist for it next time round.

 

When I'm load testing, I use a rear bag and I find that helps a bit. I still have sessions when I feel at the end of it I've proved nothing and have to redo the test. Another thing to consider is the order in which you shoot your groups. I'll sometimes take a set of five loads out to test. I'll fire a fouling shot and then I shoot a round from each load at a different target. Then have a break then reverse the order and shoot another round at each target. Then I will have another break and fire the last round of each load.

 

Good luck. JCS

[roeboy]

I tend to think like you on barrels. Why 1:8 by the way? Yes shot the groups in series so each powder charge had its fair share of barrel warming.

[jcampbellsmith]

I tend to think like you on barrels. Why 1:8 by the way? ....

If you look closely at my Avatar you'll see a Sako 75 with a 1:8 Border Barrels Archer barrel. This rifle originally had a a 1:10 twist 26 inch varmint barrel, but after putting 105 A-Max sideways through a target, I had it re-barrelled to the faster twist.

 

Regards JCS

[roeboy]

Ah I see!

[The_Dogge]

Barrels are a consumable, dont "worry" about barrel life, but be aware that not all loads are equally harsh on your barrel and you can choose to run it "full throttle" and take the hit or pick a milder load and have a longer barrel life. Powder choice makes a big difference. The speeds you are talking about are very good for the 87gn V-Max.

 

Again just from the spreadsheet estimator:

44.5gn H414, 55000 psi: Barrel life 1289 shots (mine is starting to feel a bit rough in the throat I think at about 1050 shots, but still shoots well)

38.3gn N140 (Lee data max load) 55000psi: Barrel life 2379 shots.

 

According to Lee's data it is 200ft/s slower, so you take your choice, 200ft/s or another 1000 rounds barrel life, your call. :-)

[roeboy]

Yes I may back off a bit but stick to h414. N140 is brilliant but I'm saving that for my deer rifle as vit won't be around for much longer ?

[kent]

Just my basic and broad test at 100yds. Lets me know roughly what's going on throughout the spectrum.

 

May I ask how much yours had to jump?

 

I've only got a 0.6" group so far with the 87s, isn't as satisfying as those bergers

I only consider 100yds a fair test for a .243 if that's all your likely to shoot at OR your just looking for the pressure limits or velocity testing. I don't believe in messing around with jump with most bullets in a hunting rifle, if the chamber is specifically cut or if your on VLD's etc fair enough, other than that its a bit of a fools errand as far as my results go. Case in point most factory .243 win will shoot 55's rather darn well but you wont get them anywhere close to the rifling. Hunting rifles need clearance, competitive rifles are another matter- just my thoughts and experiences, I used to think different once over