First round blues

[Miseryguts]

Ok, so I can work with first round thru a cold/clean barrel being a little way ward, but every string?

Doing load developement today with my 45-70. Three strings clocked by Labradar over the space of around 60 minutes, each string taking around 15 to 20 minutes

String 1 10 shots 300gn bullet usual load, to check scope zero - as expected, first shot a flyer followed by a reasonable 9 shot group

shot 1 1055fps, shots 2 to 10, 1103 to 1119fps ( Av. 1108 ES 17 Sd 7.7 if ignore shot1)

String 2 10 shots 400gn bullet, load A

shot 1 1009fps, shots 2 to 10, 1045 to 1066fps  ( Av. 1055 ES 21 Sd 6.3 if ignore shot 1)

String 3 10 shots 400gn Bullet, load B

shot 1 993fps, shots 2 to 10, 1063 to 1091fps ( Av. 1081 ES 28 Sd 8.5 if ignore shot 1)

So why is the first round of each string so crap?? All bullets are H&N TC with copper plating and plastic coating

M (still miserable in sunny (for now) Monmouthshire)

[force64]

Happens to me as well.  Marlin 1895 26" Octagonal barrel

 

Andy

[Miseryguts]

11 hours ago, force64 said:

Happens to me as well.  Marlin 1895 26" Octagonal barrel

 

Andy

Hi Andy, good to know it is not just me! Being of an enquiring mind, I would really like to know why. My rifle is the Henry single shot, hence the sub sonic MV as this is a very light rifle and the recoil with the 400 or 405 grain bullet at 1500fps is more than my old arthritic shoulders can stand!!

M

[Popsbengo]

What powder are you using ?  Is this a light load of pistol powder?

Are you loading your magazine or single loading?

[Miseryguts]

10 minutes ago, Popsbengo said:

What powder are you using ?  Is this a light load of pistol powder?

Are you loading your magazine or single loading?

Powder is Green Dot, 10.3gr for 300gr bullet,  Load A 11.5gr for 400gr bullet.

Load B 12gr for 400gr bullet. Load B is the most accurate

Henry Single shot rifle, so no magazine

M

[Popsbengo]

There's a lot of volume in a 45/70 case and your light load of powder is 'sloshing' about in there.  Combustion is likely to be variable.  Why only the first round?? I can't explain.

I load full power 405gn and never experienced any first shot issued.  Some mates use Unique (a touch slower than Green Dot) and they've not experienced your issue, or at least, they've never noticed 😀

You could try an inert filler (there's plenty of stuff about techniques etc on t'internet)

 

[Miseryguts]

2 hours ago, Popsbengo said:

There's a lot of volume in a 45/70 case and your light load of powder is 'sloshing' about in there.  Combustion is likely to be variable.  Why only the first round?? I can't explain.

I load full power 405gn and never experienced any first shot issued.  Some mates use Unique (a touch slower than Green Dot) and they've not experienced your issue, or at least, they've never noticed 😀

You could try an inert filler (there's plenty of stuff about techniques etc on t'internet)

 

That's what gets me - the rest of the shots in the string have low ES and single figure Sd. I use the Green Dot on subsonic 308 loads, and have no problems in that case. I have some Unique, so I can try some of that. Thanks for your thoughts

M

[terryh]

M,

Clean/cold bore shot can be different, for me it is one of the characteristics you need to know about your rifle(s).

But to resolve your problems lets apply Ockham's razor,  you could eliminate one thing by not cleaning your rifle between strings (that removes the 'clean bore') and the other by firing a couple of warming shots before you start (removing the cold bore from the equation)

Then see what happens to your results?

Brgds Terry

[Popsbengo]

1 minute ago, terryh said:

M,

Clean/cold bore shot can be different, for me it is one of the characteristics you need to know about your rifle(s).

But to resolve your problems lets apply Ockham's razor,  you could eliminate one thing by not cleaning your rifle between strings (that removes the 'clean bore') and the other by firing a couple of warming shots before you start (removing the cold bore from the equation)

Then see what happens to your results?

Brgds Terry

Didn't read it as M cleans between strings and he identified first round through clean/cold barrel as expectedly wayward.  I may be wrong but the problem seems to be understanding why the first round of a string through a barrel that's had fouling shot(s) goes wayward

[terryh]

My bad, read it wrong

My 'accurate' 22rf does not perform well from a cold bore in any condition, if i was shooting a comp target I would fire a couple of warmers.

Perhaps these soft bullet, all be it coated, perform the same way, so if the 1st round is always crap might just have to live with it?

T

[Popsbengo]

55 minutes ago, terryh said:

My bad, read it wrong

My 'accurate' 22rf does not perform well from a cold bore in any condition, if i was shooting a comp target I would fire a couple of warmers.

Perhaps these soft bullet, all be it coated, perform the same way, so if the 1st round is always crap might just have to live with it?

T

Yes my CZ455 .22LR has a predictable error too.  First shot from a stone-cold but otherwise uncleaned barrel always goes high and left.  From then on it's spot on enough for bench-rest accuracy (in it's class).  If I put the rifle down and shoot it an hour or so later it's fine.  If I shoot it next day, it's high and left !  This is with RWS, CCI and Eley ammo.  Weird 😊

[Triffid]

You're focusing on the ammunition. Could it be something to do with the chronograph instead? Is there a delay between each string?

I recall Laurie Holland experiencing something like that in his primer tests.

 

Triffid

[Popsbengo]

3 minutes ago, Triffid said:

You're focusing on the ammunition. Could it be something to do with the chronograph instead? Is there a delay between each string?

I recall Laurie Holland experiencing something like that in his primer tests.

 

Triffid

that's an excellent point, I've not noticed any aberration with my Labradar but it's worth checking out

[Miseryguts]

I have been using the Labradar on lots of different calibres (I have rifles with 7 different calibres) and I have not seen this effect on any other strings. Even if I am shooting a long string of a particular calibre, it is always in batches of 5 or 10(5 or 10 shot groups), and never seen this effect before. I will check back as I have not deleted any strings yet, so they are all still on the memory card for the last 4 months.

I suppose it may be down to the delay in between strings in the case of the 45-70, so I will try and test that out on a specific load  next time I take it out. So far I have only been trying small batches of different loads.

M (still puzzled and blue in now wet Monmouthshire)

[Triffid]

I did a bit of looking on some US forums. There is some talk of discrepancies when the battery is running low, with suggestions that using an external battery.

I have no experience with the Labradar, but those first shot on each string being consistently 50-60fps lower than the next nine makes me think that it's the instrument.

Triffid 

[Miseryguts]

4 hours ago, Triffid said:

I did a bit of looking on some US forums. There is some talk of discrepancies when the battery is running low, with suggestions that using an external battery.

I have no experience with the Labradar, but those first shot on each string being consistently 50-60fps lower than the next nine makes me think that it's the instrument.

Triffid 

Hi T I run this unit with an external source, so it is not a run down battery. I take your point on the likelihood of equipment malfunction, so I will be running some tests next time out.

Having said that, I have checked back on the last 40 or so strings of shots on various calibres, and in the past it has always been the first shot of the day that was wayward, and subsequent strings have been as expected. Ho Hum

M twiddling his thumbs in wet Monmouthshire

[KABOOM]

On 3/17/2020 at 4:04 AM, Popsbengo said:

There's a lot of volume in a 45/70 case and your light load of powder is 'sloshing' about in there.  Combustion is likely to be variable.  Why only the first round?? I can't explain.

I load full power 405gn and never experienced any first shot issued.  Some mates use Unique (a touch slower than Green Dot) and they've not experienced your issue, or at least, they've never noticed 😀

You could try an inert filler (there's plenty of stuff about techniques etc on t'internet)

 

Your right on track! My only added thought is maybe make sure you tip the round skyward to flow powder to the primer and maybe have better ignition, perhaps the word should be consistent?

 

[VarmLR]

Could it simply be a warming barrel?  I've seen this many times with lighter sporting barrels where shot one, and sometimes shot 2 are off, with the rest forming a relatively consistent group as the barrel warms on the string, only for the groups to go "off" again after 5 or 6 shots.  As Terry says, it may just be one of those things to note with that particular load with that particular rifle.

The only other culprit I can think of is change of cheek weld which affects parallax of the sight picture.  In fact that's something I needed to specifically work on before I realised it was having a massive impact on my group consistency in the early years.  Sometimes it is an unconscious action whereby your eye comes to rest fractionally off from the first shot as you settle back into a string.  It tended to be the first few shots with me before I settled into better discipline.  Once I did, the results started getting better...a lot better, so it had nothing to do with the rifle in the end.

[Miseryguts]

14 hours ago, KABOOM said:

Your right on track! My only added thought is maybe make sure you tip the round skyward to flow powder to the primer and maybe have better ignition, perhaps the word should be consistent?

 

Hi K, I do that as a matter of course in the case of the 45-70, the rifle is a Henry Single shot model H015 and as such as one loads this happens almost automatically. I do run a 308 BA with a subsonic load of the same powder, and get no effects there loading from the magazine.

2 hours ago, VarmLR said:

Could it simply be a warming barrel?  I've seen this many times with lighter sporting barrels where shot one, and sometimes shot 2 are off, with the rest forming a relatively consistent group as the barrel warms on the string, only for the groups to go "off" again after 5 or 6 shots.  As Terry says, it may just be one of those things to note with that particular load with that particular rifle.

 

Varm, that does sound like a reasonable answer. The rifle is a Henry single shot and quite light weight ( hence the reduced subsonic loads - the full pace loads are too much for my arthritic shoulder)

Thanks to all who have replied, unfortunately I cannot do any further testing on this as I think that using the  un-moderated 45-70 on my house range might be a step too far! The 22 and subsonic 308 are whisper quiet (no ear  protection needed) but none of my other rifles are moderated or using subsonic ammo, so gathering dust in the cupboard!

M ( looking at subsonic loads for his 223 in chilly Monmouthshire)