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Popsbengo

Bullet Jump

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3 hours ago, Popsbengo said:

Jamming causes higher starting pressures but does that result in faster bullet acceleration (evidenced by higher Mv) thereby reducing travel time ?? 

Dont go there, it really doesnt matter.

There aren't any good reasons for jamming a bullet unless it was the only place the barrel would shoot well enough and if that was the case i would be looking at different bullets.

MV and barrel time in itself isn't the be all and end all, there are different ways to tune a barrel and barrel timing is only one.

I know people shooting sub 2" 5 shot groups at 1000yds with an ES of as much as 40fps. A book or ballistic app will tell you that isn't possible based on the vertical spread yet its happening every summer in 1000yd BR in the US because the guys are tuning their barrels via a method called Positive Compensation.

PC tuning means the slower bullets leave the barrel later when its higher on its climb during the harmonic up and down phase than the faster ones that will leave sooner, the minute differences in trajectory based on barrel position during its harmonic cycle mean all the bullets converge at the same vertical place at a set distance you have tuned the load to. This of course means the load is only tuned for say 1000yds or 600yds etc and the convergence pattern isn't right at any other distance but the theory works and I have proved it to myself numerous times in testing. In fact Ive shot this method and won comps using it.

Of course it doesnt have to be that complicated, find a stable powder and then node then tune the seating depth, thats plenty good enough for most people most of the time, myself included.

Here is a picture of my long range BR rig during a nice day of PC testing at 600yds. Flags every 200yds and and sometimes I would be there for 6hrs just waiting for the wind to be right. Ive seen days when there wasnt a breath of wind in the late afternoon and evening and the consistency of the testing was amazing as well as the results. 

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I dont chase the lands. Nor do I reform met plats. Tipped projectiles make that un needed.  If I used a hp design and the met plats were deformed in some way I would maybe. Or replace the projectile. The adage dont screw with "it" its working seems to apply. Parts of this subject tbh im still wrapping my brain around. The ability of the shooter to remain consistent has a huge impact on results no matter the course of fire. Great topic gents I will need to revisit it and ponder.

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I've wondered for a while now why Berger don't make bullets with ballistic tips..

I asked that question on accurate shooter and the only reply was checkout articles that Bryan litz has done but I've not come across that particular subject yet.

I do point my 7mm hybrids I use for f class as do most.

The tipped bullets do seem to have a higher BC than non tipped.

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I would think the traditional full jacketed non tipped bullet will be considerably more accurate in terms of its dimensions than a bullet that has had a moulded plastic tip shoved in the end as a secondary operation.

I cant think of anyone shooting to the highest levels of precision that does it with a plastic tipped bullet. 

The aim in producing consistently good bullets is uniformity and bullets all coming from the same die with full jackets will be very uniform as there isn't any secondary operation where a stack up of errors could occur. A one piece part is always going to be easier to make well than a two piece part.

Just make sure all your bullets are from the same batch with the same batch numbers and even then check for uniformity amongst the boxes if you want to be sure of the best you can be.

I once measured and compared three batches of 500 bullets from JLK (an American custom bullet maker), Berger Hybrids and Sierra Matchkings and the results were interesting. JLK came out top, Sierra were quite a close second and the gap from Sierra to third place Berger was quite a bit bigger than the gap between first place JLK and second place Sierra.

As for Hornady, Ive seen some shocking variations in bullets from the same brand and weight albeit different batches. Hornady make some very good bullets for different applications so Im happy to use them but would always buy in batches and check at least 20% from each box against the other boxes before setting out on load development, consistency is everything.

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According to Hornady there eldm bullets are the best out there with there AMP jackets and new tip that doesn't deform with top bc doplar radar proven 😁.

I've used the 180gr ELDM's in my saum and 284 there very accurate.

Had 3 suspected blow ups with the 180s in my tiring saum barrel.

I batch weigh and measure sort the 180s but only batch weigh the 162gr ELDX's for hunting.

In all fairness there pretty consistant..

I've not used jlk's but the 7mm 184gr hybrids are about the most consistant bullet I've used too date, I've gotta box of 7mm 183gr smks the measure and weigh very consistant, not got around to trying them yet 

Recently got the 7mm 162gr ELDX's working in my 284 very nicely.

The new A tip bullets are ment to be the best of the best with a bc to go with the new aluminium tip.

I'm yet to try them as I've too many 184gr hybrids to use up first and these A tips are a quid each retail 😳. If these bullets start dominating the competitions we my have no choice but to use them to be competitive. I know some have been experimenting with them before the lockdown started..

No feed back as yet, I'm talking about the 30 cal 230gr A tips in the 300wsm..

Not sure if the 7mm 190s have made it across the pond yet..

From what I've read the 190s won't suit my freebore anyway as my saum is throated for 184gr hybrids.

Not sure about the tip being added after is a bad thing as it does uniform the from end of the bullets, some of the meplats can be irregular as baldie describes..

I point mine so they are somewhat improved, they could be trimmed then pointed but something I've not got around to doing thus far. 

I would of thought the meplat/tip is really important as this part doesn't get scarred from the rifling grooves that steers the bullet..

I don't know what the perfect bullet is but there is a variety of good ones out there now.

 

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Bullet weight variation is only one aspect, it's much more important if the weight is unevenly distributed (eg a void), especially around the long axis.

I have limited experience with Berger's but the box of 30cal 185 Juggernauts I recently bought are almost perfect in their meplat form and there's no significant weight variation.  I'm a huge fan of Lapua Scenar but I'm extremely impressed with the Berger performance.  Hornady ELD-M are very good in .338 cal. and better than the 300 Scenar (at +1600) but I've not yet tried Berger as yet.   It's an embarrassment of riches really - all excellent.

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I use a variety really.

i always go to sierra first, as their bullets are always good quality, affordable, and most importantly, available.

Their current target offerings all seem to be of the new type, with a factory pointed meplat , which is clean, square and proper. Always a bonus....

They are bringing new stuff out regular, I got in a few 6mm 107 and 110's yesterday, and these look very interesting, as a "heavy for cal" bullet with great BC's.

The only tipped bullet i use is the ELDM in 225 grain in my Norma Mag. After working up a load, I shot it the next day at Diggle in a 1000 yds F class friendly.

During the "blowing off" period, i hit a tennis ball, 4 shots in a row, and the gun [an AXMC, i Barrelled ] finished one point behind the winning F class score.

Those work nicely.

If you fancy a tipped bullet, check out Pete at MME bullets, he makes some very nice stainless tipped bullets, at a far better price than A-tips.

Upon giving some a once over, I was staggered by the quality. Every bullet was actually identical in weight and measurement....but they are handmade.

Not tried them at range yet, but certainly good at 100 yards.

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I will checkout these MME bullets 👍

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9 hours ago, baldie said:

 

They are bringing new stuff out regular, I got in a few 6mm 107 and 110's yesterday, and these look very interesting, as a "heavy for cal" bullet with great BC's.

 

Dave,

Are the 110g 6mm the new A tips? If so where did you obtain them as i'd like to try a few.

Cheers T

 

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Perhaps im missing something with this Positive Compensation seems harmonics would be exclusive to the load and if the slower load groups better you did it? I maybe really off base and hope I may learn something here. As I don't shoot at 1k yards for any reason I defer to the knowledge of those who do. As for reworking met plats if the tipped projectile wont do what's needed I sure would reform met plats and see what changes I would hope the newer ELD isn't deforming as I have read the older A -Max did, haven't seen a thing on the newer TMK deforming in flight. The idea of handmade projectiles costing less than A-tip shatters my mind. Cost has to be a huge factor in the shooting sports over there. 

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Just a side bar, I just located .224 90grn  A-Tip for 73 cents a per in USD I wonder just how expensive they are over there.

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In general UK prices are similar to US dollar  ie 1to 1 so we're paying about 30% more.  A box of Berger 30cal 185 Juggernauts are £71 per 100 at the moment.

Euro stuff is dependant on exchange rates and our VAT (sort of national sales tax at 20% for manufactured goods etc).

A question for you guys in the States:  when a price is shown on a US website, is there State tax to add to that, or is the listed price the total price you pay for the goods?

My brother lives in Maine so it may work out for him to buy small items (non-controlled) and ship to me.

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21 minutes ago, Popsbengo said:

In general UK prices are similar to US dollar  ie 1to 1 so we're paying about 30% more.  A box of Berger 30cal 185 Juggernauts are £71 per 100 at the moment.

Euro stuff is dependant on exchange rates and our VAT (sort of national sales tax at 20% for manufactured goods etc).

A question for you guys in the States:  when a price is shown on a US website, is there State tax to add to that, or is the listed price the total price you pay for the goods?

My brother lives in Maine so it may work out for him to buy small items (non-controlled) and ship to me.

Great bear hunting in Maine, so I have heard. 

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22 minutes ago, Popsbengo said:

In general UK prices are similar to US dollar  ie 1to 1 so we're paying about 30% more.  A box of Berger 30cal 185 Juggernauts are £71 per 100 at the moment.

Euro stuff is dependant on exchange rates and our VAT (sort of national sales tax at 20% for manufactured goods etc).

A question for you guys in the States:  when a price is shown on a US website, is there State tax to add to that, or is the listed price the total price you pay for the goods?

My brother lives in Maine so it may work out for him to buy small items (non-controlled) and ship to me.

Yes state tax is now added on mail order thanks to our (wonderful) congress. As I despise taxes any how it rankles me. However freight tends to  be cheaper than fuel when the closest outlet is 25 miles one way. If that has nothing add 30 more miles one way. I don't go just for shooting supplies. Best wishes for good shooting.

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12 hours ago, terryh said:

Dave,

Are the 110g 6mm the new A tips? If so where did you obtain them as i'd like to try a few.

Cheers T

 

No Terry, sierra match kings, but the new style they all seem to now be, with a factory point.

Stunning bullets.

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Cheers Dave, will take a look.

Reading this thread jogged my memory - , think I’ve a bullet pointing setup for 6mm from my Swiss match ‘days’ out in ‘the shed’, might dig out

more specifically found this article which has data on my current 6mm bullet, worth a try? ; https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

T

 

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On 6/28/2020 at 11:04 AM, Big Al said:

I talk every week with guys about load development and its clear that at least 50% dont really know what they are doing and even others who do still dont do it thoroughly enough to achieve the levels of accuracy and consistency they want.

🙋‍♂️

Ahem - I'm definitely in that box!!

I had a Sako 243 years ago that I worked a load up with my brother (who'd done a bit of reloading, but not much). We basically bumbled into a combo that worked very easily and it shot .2" 5 shot groups. False sense of security - load development is clearly easy!! So when I had that rifle rebarrelled a good few years later, I was pretty clueless about working up a load - no access to Quickload, very limited access to a chrono - not really much idea about what I was doing and wasn't helped by the chap at the range I was using who sounded like he knew what he was doing, but in hindsight probably knew as much as me! 

I spent a fortune on powders and bullets chasing an accurate combo, but without testing each combo thoroughly so looking back, I'm convinced I missed some accurate loads in there and dismissed a powder or a bullet too early.

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