280rem and 175 mk's

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Ian D
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Joined: Fri Jul 13, 2007 5:56 pm
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Location: Mount Ousley, NSW

280rem and 175 mk's

Post by Ian D »

does anyone have any experience or info
on shooting 175 mk's or 180 berger vld out of a 280rem improved fly rifle.I know they work good out of a straight 284 win which has similar capacity?
thanks Ian D
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albow
.257 Roberts
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Joined: Fri Oct 20, 2006 7:40 am
Location: Nth Queensland

Re: 280rem and 175 mk's

Post by albow »

Ian

Drop TZ a line he will have the info you are chasing but the guys up here seem to get better results and prefer the 168 mk's.
Tony Z
.270 Winchester
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Joined: Fri Oct 27, 2006 5:29 pm

Re: 280rem and 175 mk's

Post by Tony Z »

How goes things Ian?

Mate, some time a go i did a lot of work with the 175s in 3 barrels and 2 cartridges. Two barrels were chambered in the 280 AI version we did using the 9.3 case. The capacity is virtually identical to the 280 you use and the 284 Win others use. The third barrel was in a big 7 mm Magnum. All three barrels were very good with the selected batches of 162 Amax and all batches i ever used in 168 SMK. The 168 Berger i used once in the Magnum and won a Fly match with it. So the barrels were already proving themselves. But with the 175s, all three barrels showed flashes of brilliance and then flashes of not so good. None were ever consistent enough to instill enough confidence to shoot a match with. So i never did. I fired 800 175s through these three barrels with a multitude of powders and primers etc, and nothing really changed other than they remained inconsistent.

What is common knowledge is the guy who was going to do the action and barrel fitting for you in the US, is the guy who developed the 175 SMK. What is not common knowledge is that the bullet he developed and the one Sierra put to the market are two completely different bullets. The original one was field tested at 1K for thousands of shots, and the bullet we can buy now is a product of a computer as i have come to understand it. The field tested bullet had a polymer insert, the one you have now does not. Jeff Rogers can expand on this at length because he was in contact with him all the while this testing was going on. Jeff was in the process of building a 7mm Redneck of which i made the reamer for in anticipation of this great new bullet coming out. We got the first bullets that came into the country because JR spoke to our importer, who knew nothing of this bullet at all, but ordered them on JRs insistence.
The original field testing of this bullet was done in a 280 AI on the same RWS brass you use. He used the same powders you and i use. But his results are not what we are getting. What i did to get the 175 SMKs to work was meplat cut them 40 to 50 thou short and shoot them like that. They shot great but had the trajectory of a house brick. So i and everyone else i know went back to the 168 SMK. Somewhere along the line, the bullet was pointed up to be what it was when it had the insert. The problem with that is that they changed dynamically with the weight of the extra copper out front. I do not know if the more recent batches have a different profile but if they are shorter than 1.440" inch average, then they are a different bullet to the four batches i used very early in the piece.

Marty Lobert, the FO shooter, has used these bullets in his 284 very successfully but at a window of velocity around 2820 fps. Slower than that is still OK, but faster and the erratic nature of this bullet creeps in. The problem with this is that the extra velocity of the 168 SMK of aroud 3000 fps with its real world BC of around .550 will arrive at the target first and higher up the paper than what the 175 will at 2820 fps at the 1K range. Zero gain, or an actual loss. The beauty of the 168 is they will stabilize in a 1 in 10 twist or 1 in 11 like what i liked to use and the uplift was cut down a bit. Win win all around.

There is no doubt the 175 has the BC. There is also no doubt that the 168 SMK has the accuracy that very few bullets i have seen have and it is no fluke that many of my small group trophies at Fly matches have come with this bullet. The choice comes down to accuracy over BC and i pick accuracy every time. Trying to combine the two is very rare. But hey, you did it with the 180 Berger so i can't argue with that.

Best of luck Ian. Give me a call and i will relay all the load data i have, but 50.5 grains of 2209 and 57 grains of Re22 are a good area straight up. But be careful with the Re22 as that shit can really spike. See the target pic attached where i used my old LG to shoot these bullets and a couple of different powders. With 2 1/4 inches of vertical, these loads which were about as good as it ever got with the 175, are just not acceptable for what we need.

Tony Z.
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