Beardog Posted August 25, 2018 Report Share Posted August 25, 2018 Hi Anyone know what sort of muzzle velocity I can expect to get with .204 20” barrel, IMR 4895 and 39g.SBK. Had pretty much the same size groups with 27.4, 27.6, 27.8 and 28g. With 27.6 was slightly the best group. Can’t imagine there is much MV difference with 0.6g of variation. Want to get the load shooting as flat as possible. Pressure signs all good, scope for higher load but maxed out on case volume pretty much. I wrote the above yesterday but didn’t post it. So today I loaded up 50 rounds at 27.6g of IMR 4895. With the following results each a three round group with one factory round too with a clean rifle. 200y 55mm 2” low 250y 140mm 5.5” Low 300y 220mm 8.5” Low 350y 380mm 15” low. All grouped well and at each distance I tried a factory Hornady 40g which dropped lower than my new load. Feeling disappointed with the performance. Had hoped they would be flatter. Once finished I put my pulsar n355 back on. Zeroed it at 100y and then things got weird. Went back to 250y and hit bang on, hardly no drop. (red 4” circle on Hardox plate). Should of been about 5.5”. Then went a little further back to 270y and still bang on pretty much. (Hard to get a consistent poi with pulsar but best I could) No idea what has happened there. If anyone knows how to work out my MV I’d be grateful. Cheers. Link to comment Share on other sites More sharing options...
GT3_richy Posted August 25, 2018 Report Share Posted August 25, 2018 27.6gr I would guess is warm - surprised you arent seeing at least some flat primers. A guestimate from Quickload suggests you to be 1-2K psi over saami max. pressure for about 3610fps with a 20" barrel. I'd imagine its a bit less in reality as I run 39s at not much over 3500fps with an inch or two less drop at 300 from recollection. 28gr will probably get you an extra 50fps or so. Link to comment Share on other sites More sharing options...
Elliott Posted August 26, 2018 Report Share Posted August 26, 2018 Here's the data from the Hodgdon webpage with a 40gr bullet and 24" barrel. This data is usually exaggerated, so I'd say you'd be lucky to hit 3,600. Perhaps 3,500fps. I've uploaded a data sheet from Strelock. 100 yard zero, 39gr SBK at 3,500fps. Looks like you might even be slower than that. Link to comment Share on other sites More sharing options...
treetop Posted August 26, 2018 Report Share Posted August 26, 2018 The height of the scope may answer why you suddenly don't get the same drop off. as most NV units are about 3" from the middle of the lens to the middle of the bore & most people tend to get the scope as low as possible, this gives a difference in POI over distance. Probably not as much as you have seen but may be some kind of answer. I would also hazard a guess that the dot or cross on the NV is a lot bigger than your scope Link to comment Share on other sites More sharing options...
Beardog Posted August 27, 2018 Author Report Share Posted August 27, 2018 Hi Many thanks for replies. Treetop, you could well be right there ref scope height. Just added the extra scope height into my ballistic AE app and it does make a difference. So could in part explain the variations. I added the round data into the app and trued the MV with my real world drop data and it gave the MV as 3296. I would expect an actual chrono reading to be within 100 of that. Disappointing results really, was still better that factory ammo but only just. Will try another powder I think. Was hoping for a much flatter load. I have the pulsar N355, it’s very good. Loads of different cross hairs to try, very fine. Had a Charlie tonight with the new load, did it’s job nicely. Cheers Link to comment Share on other sites More sharing options...
Elliott Posted August 27, 2018 Report Share Posted August 27, 2018 It's not cheap, but give Vhit N530 a try. It's what I'm using in my 204. My CZ has a 25" barrel and the 39gr SBK's are clocking 3,740fps with 25.6gr. Link to comment Share on other sites More sharing options...
Beardog Posted August 27, 2018 Author Report Share Posted August 27, 2018 Will do Elliot. I’ve got some n140 n133 and n540 I use for other loads. Will load a few with the n540. Cheers. Link to comment Share on other sites More sharing options...
rimmie Posted August 27, 2018 Report Share Posted August 27, 2018 Try reloader 10X also Link to comment Share on other sites More sharing options...
GT3_richy Posted August 27, 2018 Report Share Posted August 27, 2018 Another vote for N530, I get +/- 3500fps with 25.6gr from a 20" barrel. 10x and RS40 would also be good shouts for velocity if you can get them locally. I had good accuracy from N133 but the velocity was well down, N530 seems to be the sweet spot for mine. Link to comment Share on other sites More sharing options...
Beardog Posted August 27, 2018 Author Report Share Posted August 27, 2018 Tried some N133 and N140 this afternoon. Accurate loads. N140 wasn’t any good. The N133 was slightly better than IMR I tried. 39g SBK n133 25.3 200y 45mm 1.8” 250y 95mm 4” 300y 200mm 8” 39g SBK n140 28g 200y 50mm 2” 250y 150mm 6” 300y 240mm 9.5” Have to try some other powders Link to comment Share on other sites More sharing options...
treetop Posted August 27, 2018 Report Share Posted August 27, 2018 8208 XBR CFE 223 Link to comment Share on other sites More sharing options...
Bob57 Posted August 27, 2018 Report Share Posted August 27, 2018 Hi beardog,not sure you'll ever get it as flat as you want with a 20" barrell !!.this might or might not help but here goes. I'm shooting 39 sbk's,*HBN* coated out of a 24" barrel with 26.8grns of VN133 @ 3783 FPS AV,dropped 2"@ 250yds,the load I have stayed with☺. Had another great load with 28.2 grns of H4895, 39sbk's *HBN*coated @ 3796fps AV which dropped 6" @300yds. Neither of these loads showed pressure signs with the bullets being coated with HBN in my rifle but work up if trying!! . Also when doing load development I noticed a bit more velocity with more jump to the lands (65 thou jump). Link to comment Share on other sites More sharing options...
Beardog Posted August 28, 2018 Author Report Share Posted August 28, 2018 Thanks for reply Bob57. Always appreciate any inputs. Starting to seem I won’t get it as flat as I hoped. Loads so far Definitely quicker than factory ammo. Trying to get some other powders to try, no one has anything! Powders tried so far hardly better than factory ammo. Going to try CFE 223 and x10 or N530 if I can get any. N133 best so far. Still had a Charlie last night which cheered me up, with the 39g SBK, hardly ever any damage with these fast rounds on body shots. Link to comment Share on other sites More sharing options...
GT3_richy Posted August 28, 2018 Report Share Posted August 28, 2018 Whereabouts are you Bear? Link to comment Share on other sites More sharing options...
Beardog Posted August 28, 2018 Author Report Share Posted August 28, 2018 Hampshire/Surrey border. Link to comment Share on other sites More sharing options...
Bob57 Posted August 28, 2018 Report Share Posted August 28, 2018 3 hours ago, Beardog said: Thanks for reply Bob57. Always appreciate any inputs. Starting to seem I won’t get it as flat as I hoped. Loads so far Definitely quicker than factory ammo. Trying to get some other powders to try, no one has anything! Powders tried so far hardly better than factory ammo. Going to try CFE 223 and x10 or N530 if I can get any. N133 best so far. Still had a Charlie last night which cheered me up, with the 39g SBK, hardly ever any damage with these fast rounds on body shots. No probs beardog?.sounds like you're going to spend a fortune on powder chasing a few FPS,if I was you I'd go straight to vn530, from data I've seen its prob the best for speed but worst for your rifle's throat!! .I bought a tub about 9 months ago but haven't tried it yet,will post findings when I do.i know what you mean about no visable damage but insides are mush,brilliant bullet for such light weight. Link to comment Share on other sites More sharing options...
GT3_richy Posted August 29, 2018 Report Share Posted August 29, 2018 5 hours ago, Beardog said: Hampshire/Surrey border. I have probably most of a tub of 10x you can have cheap. There may be an unopened tub of 530 you can have if you replace it, will need to check what I have left. Isn't there any at Bisley you can go and grab? Link to comment Share on other sites More sharing options...
baldie Posted August 29, 2018 Report Share Posted August 29, 2018 If you want flat, switch to 32 grain bullets. You dont have the barrel length to get the speeds you require, with any powder and a 39. The .204 needs a 26" barrel to get the real fast speeds, its overbored. Interestingly enough, the 20 practical will, or certainly a lot closer. CFE223 is , i believe the powder that factory ammo is loaded with. Link to comment Share on other sites More sharing options...
Beardog Posted August 29, 2018 Author Report Share Posted August 29, 2018 If thats true, that factory ammo is loaded with CFE 223 then thats quite funny. Yes I know the 32g would be flatter, just prefer the 39/40g bullets. Link to comment Share on other sites More sharing options...
Bob57 Posted August 29, 2018 Report Share Posted August 29, 2018 I gave up trying to get a good group with 32grn hornadys,thought I'd use them on the bunnies but just couldn't get them shooting. Link to comment Share on other sites More sharing options...
hunter686 Posted August 30, 2018 Report Share Posted August 30, 2018 Give this a shot: 27.4gr N135. I know 5 guys in total that shot this load out of a 20' Tikka and it went lights out in all of them. They come in at around 3750fps. The best group i ever shot on this load was 1/4" at 314 yrds with the 39 SBK. I previously used 10X and although it worked for a lot of guys my Tikka HATED it Link to comment Share on other sites More sharing options...
Beardog Posted August 30, 2018 Author Report Share Posted August 30, 2018 Hi 686 what sort of bullet drop are they getting with that load? Link to comment Share on other sites More sharing options...
hunter686 Posted August 30, 2018 Report Share Posted August 30, 2018 15 minutes ago, Beardog said: Hi 686 what sort of bullet drop are they getting with that load? Can't remember as I don't have the rifle any more. Just put the fps up to 3730 on your BC for the 39s and it won't be too far off Link to comment Share on other sites More sharing options...
Bob57 Posted August 30, 2018 Report Share Posted August 30, 2018 Probably be similar to mine, 2" @250 and 6"@300. Link to comment Share on other sites More sharing options...
Beardog Posted September 4, 2018 Author Report Share Posted September 4, 2018 Managed to get some 10x today! So hopefully that will prove better than the others I tired. Roll on the weekend. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.